diff --git a/.changeset/fn-7451-workflow-settings-save-race.md b/.changeset/fn-7451-workflow-settings-save-race.md
new file mode 100644
index 0000000000..2f546a0a8f
--- /dev/null
+++ b/.changeset/fn-7451-workflow-settings-save-race.md
@@ -0,0 +1,7 @@
+---
+"@runfusion/fusion": patch
+---
+
+summary: Preserve workflow setting edits made while a values save is still in flight.
+category: fix
+dev: WorkflowSettingsPanel and Project Models workflow lane saves now clear only snapshot-matching pending keys.
diff --git a/packages/dashboard/app/__tests__/settings-sections.test.tsx b/packages/dashboard/app/__tests__/settings-sections.test.tsx
index 6bc0f14891..215c8f685b 100644
--- a/packages/dashboard/app/__tests__/settings-sections.test.tsx
+++ b/packages/dashboard/app/__tests__/settings-sections.test.tsx
@@ -9,8 +9,8 @@
  * component-test conventions in settings-primitives.test.tsx.
  */
 import { useState } from "react";
-import { describe, it, expect, vi, afterEach } from "vitest";
-import { render, screen, fireEvent, cleanup } from "@testing-library/react";
+import { describe, it, expect, vi, afterEach, beforeEach } from "vitest";
+import { render, screen, fireEvent, cleanup, waitFor, act } from "@testing-library/react";
 import * as jestDomMatchers from "@testing-library/jest-dom/matchers";
 
 import { AppearanceSection } from "../components/settings/sections/AppearanceSection";
@@ -23,7 +23,8 @@ import { PromptsSection } from "../components/settings/sections/PromptsSection";
 import { SecretsSection } from "../components/settings/sections/SecretsSection";
 import { WorktreesSection } from "../components/settings/sections/WorktreesSection";
 import type { SettingsFormState } from "../components/settings/sections/context";
-import { fetchWorkflow, fetchWorkflowSettingValues } from "../api";
+import { fetchWorkflow, fetchWorkflowSettingValues, updateWorkflowSettingValues } from "../api";
+import type { WorkflowSettingValuesPayload } from "../api";
 
 vi.mock("../components/AgentPromptsManager", () => ({
   AgentPromptsManager: () => <div data-testid="agent-prompts-manager" />,
@@ -41,17 +42,32 @@ vi.mock("../api", async (importOriginal) => {
     fetchProjectDefaultWorkflow: vi.fn(async () => ({ workflowId: null })),
     setProjectDefaultWorkflow: vi.fn(async () => ({ workflowId: null })),
     fetchGlobalSettings: vi.fn(async () => ({})),
+    updateWorkflowSettingValues: vi.fn(async () => ({ stored: {}, effective: {}, orphaned: [] })),
   };
 });
 vi.mock("../components/CustomModelDropdown", () => ({
-  CustomModelDropdown: ({ id, label, menuWidth = "trigger" }: { id?: string; label: string; menuWidth?: "trigger" | "readable" }) => (
-    <button type="button" data-testid={`mock-model-dropdown-${id ?? label}`} data-menu-width={menuWidth}>
+  CustomModelDropdown: ({ id, label, value, onChange, menuWidth = "trigger" }: { id?: string; label: string; value?: string; onChange?: (value: string) => void; menuWidth?: "trigger" | "readable" }) => (
+    <button
+      type="button"
+      data-testid={`mock-model-dropdown-${id ?? label}`}
+      data-menu-width={menuWidth}
+      data-value={value ?? ""}
+      onClick={() => onChange?.("anthropic/claude-sonnet-4-5")}
+    >
       {label}
     </button>
   ),
 }));
 
 expect.extend(jestDomMatchers);
+beforeEach(() => {
+  vi.mocked(fetchWorkflow).mockReset();
+  vi.mocked(fetchWorkflowSettingValues).mockReset();
+  vi.mocked(updateWorkflowSettingValues).mockReset();
+  vi.mocked(fetchWorkflow).mockResolvedValue({ id: "builtin:coding", name: "Coding", ir: {} } as never);
+  vi.mocked(fetchWorkflowSettingValues).mockResolvedValue({ stored: {}, effective: {}, orphaned: [] });
+  vi.mocked(updateWorkflowSettingValues).mockResolvedValue({ stored: {}, effective: {}, orphaned: [] });
+});
 afterEach(() => cleanup());
 
 const emptyForm = {} as SettingsFormState;
@@ -345,6 +361,89 @@ describe("ProjectModelsSection", () => {
     expect(await screen.findByTestId("mock-model-dropdown-workflow-planning-model")).toHaveAttribute("data-menu-width", "readable");
   });
 
+  it("preserves workflow lane edits made while the registered saver is in flight", async () => {
+    let saver: (() => Promise<void>) | null = null;
+    let resolveSave!: (value: WorkflowSettingValuesPayload) => void;
+    vi.mocked(fetchWorkflow).mockResolvedValueOnce({
+      id: "builtin:coding",
+      name: "Coding",
+      ir: {
+        settings: [
+          { id: "planningProvider", name: "Planning Provider", type: "string" },
+          { id: "planningModelId", name: "Planning Model", type: "string" },
+          { id: "executionProvider", name: "Execution Provider", type: "string" },
+          { id: "executionModelId", name: "Execution Model", type: "string" },
+        ],
+      },
+    } as never);
+    vi.mocked(fetchWorkflowSettingValues).mockResolvedValueOnce({ stored: {}, effective: {}, orphaned: [] });
+    vi.mocked(updateWorkflowSettingValues)
+      .mockReturnValueOnce(
+        new Promise<WorkflowSettingValuesPayload>((resolve) => {
+          resolveSave = resolve;
+        }),
+      )
+      .mockResolvedValueOnce({
+        stored: { executionProvider: "anthropic", executionModelId: "claude-sonnet-4-5" },
+        effective: { executionProvider: "anthropic", executionModelId: "claude-sonnet-4-5" },
+        orphaned: [],
+      });
+
+    render(
+      <ProjectModelsSection
+        scopeBanner={null}
+        form={{ defaultWorkflowId: "builtin:coding" } as SettingsFormState}
+        setForm={vi.fn()}
+        models={{
+          ...models,
+          availableModels: [{ provider: "anthropic", id: "claude-sonnet-4-5", name: "Claude Sonnet 4.5" }],
+        }}
+        projectId="project-1"
+        addToast={vi.fn()}
+        registerWorkflowLaneSaver={(next) => {
+          saver = next;
+        }}
+      />,
+    );
+
+    const planning = await screen.findByTestId("mock-model-dropdown-workflow-planning-model");
+    const execution = await screen.findByTestId("mock-model-dropdown-workflow-execution-model");
+    fireEvent.click(planning);
+    await waitFor(() => expect(planning).toHaveAttribute("data-value", "anthropic/claude-sonnet-4-5"));
+
+    const firstSave = saver!();
+    await waitFor(() => expect(updateWorkflowSettingValues).toHaveBeenCalledTimes(1));
+    expect(updateWorkflowSettingValues).toHaveBeenNthCalledWith(
+      1,
+      "builtin:coding",
+      { planningProvider: "anthropic", planningModelId: "claude-sonnet-4-5" },
+      "project-1",
+    );
+
+    fireEvent.click(execution);
+    await waitFor(() => expect(execution).toHaveAttribute("data-value", "anthropic/claude-sonnet-4-5"));
+    await act(async () => {
+      resolveSave({
+        stored: { planningProvider: "anthropic", planningModelId: "claude-sonnet-4-5" },
+        effective: { planningProvider: "anthropic", planningModelId: "claude-sonnet-4-5" },
+        orphaned: [],
+      });
+      await firstSave;
+    });
+
+    expect(execution).toHaveAttribute("data-value", "anthropic/claude-sonnet-4-5");
+    await act(async () => {
+      await saver!();
+    });
+    await waitFor(() => expect(updateWorkflowSettingValues).toHaveBeenCalledTimes(2));
+    expect(updateWorkflowSettingValues).toHaveBeenNthCalledWith(
+      2,
+      "builtin:coding",
+      { executionProvider: "anthropic", executionModelId: "claude-sonnet-4-5" },
+      "project-1",
+    );
+  });
+
   it("renders PR prompt guidance textareas and emits edits through setForm", () => {
     function ProjectModelsHost() {
       const [form, setFormState] = useState<SettingsFormState>({
diff --git a/packages/dashboard/app/components/WorkflowSettingsPanel.tsx b/packages/dashboard/app/components/WorkflowSettingsPanel.tsx
index 7034aff014..a2172d7d51 100644
--- a/packages/dashboard/app/components/WorkflowSettingsPanel.tsx
+++ b/packages/dashboard/app/components/WorkflowSettingsPanel.tsx
@@ -492,6 +492,14 @@ function rawValueDisplay(value: unknown): string {
   }
 }
 
+function workflowSettingPendingValueEquals(a: unknown, b: unknown): boolean {
+  if (Object.is(a, b)) return true;
+  if (Array.isArray(a) && Array.isArray(b)) {
+    return a.length === b.length && a.every((value, index) => Object.is(value, b[index]));
+  }
+  return false;
+}
+
 export interface WorkflowModelLanePair {
   id: string;
   providerId: string;
@@ -712,14 +720,21 @@ function ValuesTab({
 
   const save = useCallback(async () => {
     if (!dirty) return;
-    const savedKeys = new Set(Object.keys(pending));
+    const pendingSnapshot = { ...pending };
+    const savedKeys = Object.keys(pendingSnapshot);
     setSaving(true);
     try {
-      const res = await updateWorkflowSettingValues(workflowId, pending, boundProjectId);
+      const res = await updateWorkflowSettingValues(workflowId, pendingSnapshot, boundProjectId);
       setPayload(res);
       setPending((prev) => {
         const next = { ...prev };
-        for (const k of savedKeys) delete next[k];
+        /*
+         * FNXC:WorkflowSettingsSaveRace 2026-07-02-13:28:
+         * Values remain editable during an async save, so success may only clear keys whose current pending value still equals this request's snapshot. New same-key edits, clear-to-default nulls, and model-lane pair edits must remain queued for the next save.
+         */
+        for (const k of savedKeys) {
+          if (workflowSettingPendingValueEquals(prev[k], pendingSnapshot[k])) delete next[k];
+        }
         return next;
       });
       setRejections({});
diff --git a/packages/dashboard/app/components/__tests__/WorkflowSettingsPanel.test.tsx b/packages/dashboard/app/components/__tests__/WorkflowSettingsPanel.test.tsx
index 1c38318505..ef1cbdc204 100644
--- a/packages/dashboard/app/components/__tests__/WorkflowSettingsPanel.test.tsx
+++ b/packages/dashboard/app/components/__tests__/WorkflowSettingsPanel.test.tsx
@@ -82,6 +82,9 @@ const modelResponse = {
 };
 
 beforeEach(() => {
+  mockFetchModels.mockReset();
+  mockFetchValues.mockReset();
+  mockUpdateValues.mockReset();
   mockFetchModels.mockResolvedValue(modelResponse);
   mockFetchValues.mockResolvedValue(payload());
   mockUpdateValues.mockResolvedValue(payload());
@@ -89,7 +92,6 @@ beforeEach(() => {
 
 afterEach(() => {
   cleanup();
-  vi.clearAllMocks();
 });
 
 describe("WorkflowSettingsPanel — Definitions tab", () => {
@@ -272,6 +274,81 @@ describe("WorkflowSettingsPanel — Values tab", () => {
     expect(mockUpdateValues).toHaveBeenNthCalledWith(2, "wf-1", { label: "mid-flight-edit" }, "proj-1");
   });
 
+  it("preserves a newer same-key edit when an older save resolves", async () => {
+    mockFetchValues.mockResolvedValue(payload({ effective: { "timeout-ms": 1000, "new-sessions": false, label: "server" } }));
+    let resolveSave!: (value: WorkflowSettingValuesPayload) => void;
+    mockUpdateValues
+      .mockReturnValueOnce(
+        new Promise<WorkflowSettingValuesPayload>((resolve) => {
+          resolveSave = resolve;
+        }),
+      )
+      .mockResolvedValueOnce(
+        payload({
+          stored: { "timeout-ms": 7000 },
+          effective: { "timeout-ms": 7000, "new-sessions": false, label: "server" },
+        }),
+      );
+
+    render(<Host initial={decls} />);
+    openValues();
+    await waitFor(() => expect(mockFetchValues).toHaveBeenCalled());
+
+    fireEvent.change(screen.getByLabelText("Timeout"), { target: { value: "5000" } });
+    fireEvent.click(screen.getByTestId("wf-settings-save-values"));
+    await waitFor(() => expect(mockUpdateValues).toHaveBeenCalledTimes(1));
+    expect(mockUpdateValues).toHaveBeenNthCalledWith(1, "wf-1", { "timeout-ms": 5000 }, "proj-1");
+
+    fireEvent.change(screen.getByLabelText("Timeout"), { target: { value: "7000" } });
+    await act(async () => {
+      resolveSave(payload({ stored: { "timeout-ms": 5000 }, effective: { "timeout-ms": 5000, "new-sessions": false, label: "server" } }));
+    });
+
+    expect(screen.getByLabelText("Timeout")).toHaveValue(7000);
+    await waitFor(() => expect(screen.getByTestId("wf-settings-save-values")).not.toBeDisabled());
+    fireEvent.click(screen.getByTestId("wf-settings-save-values"));
+    await waitFor(() => expect(mockUpdateValues).toHaveBeenCalledTimes(2));
+    expect(mockUpdateValues).toHaveBeenNthCalledWith(2, "wf-1", { "timeout-ms": 7000 }, "proj-1");
+  });
+
+  it("preserves mid-flight clear-to-default edits after an unrelated save resolves", async () => {
+    mockFetchValues.mockResolvedValue(
+      payload({
+        stored: { label: "custom" },
+        effective: { "timeout-ms": 1000, "new-sessions": false, label: "custom" },
+      }),
+    );
+    let resolveSave!: (value: WorkflowSettingValuesPayload) => void;
+    mockUpdateValues
+      .mockReturnValueOnce(
+        new Promise<WorkflowSettingValuesPayload>((resolve) => {
+          resolveSave = resolve;
+        }),
+      )
+      .mockResolvedValueOnce(payload({ stored: {}, effective: { "timeout-ms": 5000, "new-sessions": false } }));
+
+    render(<Host initial={decls} />);
+    openValues();
+    await waitFor(() => expect(screen.getByLabelText("Label")).toHaveValue("custom"));
+    await waitFor(() => expect(screen.getByTestId("wf-settings-customized-label")).toBeInTheDocument());
+
+    fireEvent.change(screen.getByLabelText("Timeout"), { target: { value: "5000" } });
+    fireEvent.click(screen.getByTestId("wf-settings-save-values"));
+    await waitFor(() => expect(mockUpdateValues).toHaveBeenCalledTimes(1));
+
+    const labelRow = screen.getByTestId("wf-settings-value-label");
+    fireEvent.click(within(labelRow).getByRole("button"));
+    await act(async () => {
+      resolveSave(payload({ stored: { "timeout-ms": 5000, label: "custom" }, effective: { "timeout-ms": 5000, "new-sessions": false, label: "custom" } }));
+    });
+
+    expect(screen.getByLabelText("Label")).toHaveValue("");
+    await waitFor(() => expect(screen.getByTestId("wf-settings-save-values")).not.toBeDisabled());
+    fireEvent.click(screen.getByTestId("wf-settings-save-values"));
+    await waitFor(() => expect(mockUpdateValues).toHaveBeenCalledTimes(2));
+    expect(mockUpdateValues).toHaveBeenNthCalledWith(2, "wf-1", { label: null }, "proj-1");
+  });
+
   it("renders a per-field rejection on the matching row and keeps other edits applied", async () => {
     mockFetchValues.mockResolvedValue(payload({ effective: { "timeout-ms": 1000, "new-sessions": false } }));
     mockUpdateValues.mockRejectedValueOnce(
@@ -520,6 +597,48 @@ describe("WorkflowSettingsPanel — Values tab", () => {
     );
   });
 
+  it("preserves mid-flight model-lane pair edits after an unrelated save resolves", async () => {
+    mockFetchValues.mockResolvedValue(payload({ effective: { planningProvider: "", planningModelId: "", customModelProvider: "old" } }));
+    let resolveSave!: (value: WorkflowSettingValuesPayload) => void;
+    mockUpdateValues
+      .mockReturnValueOnce(
+        new Promise<WorkflowSettingValuesPayload>((resolve) => {
+          resolveSave = resolve;
+        }),
+      )
+      .mockResolvedValueOnce(
+        payload({
+          stored: { planningProvider: "anthropic", planningModelId: "claude-sonnet", customModelProvider: "saved" },
+          effective: { planningProvider: "anthropic", planningModelId: "claude-sonnet", customModelProvider: "saved" },
+        }),
+      );
+
+    render(<Host initial={modelDecls} readOnly />);
+    await waitFor(() => expect(mockFetchModels).toHaveBeenCalled());
+
+    fireEvent.change(screen.getByLabelText("Custom model provider"), { target: { value: "saved" } });
+    fireEvent.click(screen.getByTestId("wf-settings-save-values"));
+    await waitFor(() => expect(mockUpdateValues).toHaveBeenCalledTimes(1));
+    expect(mockUpdateValues).toHaveBeenNthCalledWith(1, "wf-1", { customModelProvider: "saved" }, "proj-1");
+
+    await openPlanningDropdown();
+    fireEvent.click(await screen.findByRole("option", { name: /Claude Sonnet/i }));
+    await act(async () => {
+      resolveSave(payload({ stored: { customModelProvider: "saved" }, effective: { customModelProvider: "saved" } }));
+    });
+
+    expect(screen.getByLabelText("Plan/Triage Model")).toHaveTextContent("Claude Sonnet");
+    await waitFor(() => expect(screen.getByTestId("wf-settings-save-values")).not.toBeDisabled());
+    fireEvent.click(screen.getByTestId("wf-settings-save-values"));
+    await waitFor(() => expect(mockUpdateValues).toHaveBeenCalledTimes(2));
+    expect(mockUpdateValues).toHaveBeenNthCalledWith(
+      2,
+      "wf-1",
+      { planningProvider: "anthropic", planningModelId: "claude-sonnet" },
+      "proj-1",
+    );
+  });
+
   it("shows inherited/default dropdown state for undefined values without a customized badge", async () => {
     render(<Host initial={modelDecls} readOnly />);
     await waitFor(() => expect(mockFetchValues).toHaveBeenCalledWith("wf-1", "proj-1"));
diff --git a/packages/dashboard/app/components/settings/sections/ProjectModelsSection.tsx b/packages/dashboard/app/components/settings/sections/ProjectModelsSection.tsx
index bec4af0ebc..f627fd8918 100644
--- a/packages/dashboard/app/components/settings/sections/ProjectModelsSection.tsx
+++ b/packages/dashboard/app/components/settings/sections/ProjectModelsSection.tsx
@@ -80,6 +80,14 @@ function modelPairValue(values: Record<string, unknown>, pair: WorkflowModelPair
         ? `${provider}/${modelId}`
         : "";
 }
+function workflowPendingValueEquals(a: unknown, b: unknown): boolean {
+    if (Object.is(a, b))
+        return true;
+    if (Array.isArray(a) && Array.isArray(b)) {
+        return a.length === b.length && a.every((value, index) => Object.is(value, b[index]));
+    }
+    return false;
+}
 export interface ProjectModelsSectionModelProps {
     modelLanes: ModelLane[];
     getLaneStatus: (lane: ModelLane) => LaneStatus;
@@ -208,10 +216,23 @@ export function ProjectModelsSection({ scopeBanner, form, setForm, models, proje
     const saveWorkflowLanes = useCallback(async () => {
         if (!projectId || !workflowDirty)
             return;
+        const pendingSnapshot = { ...workflowPending };
+        const savedKeys = Object.keys(pendingSnapshot);
         try {
-            const payload = await updateWorkflowSettingValues(workflowId, workflowPending, projectId);
+            const payload = await updateWorkflowSettingValues(workflowId, pendingSnapshot, projectId);
             setWorkflowPayload(payload);
-            setWorkflowPending({});
+            setWorkflowPending((current) => {
+                const next = { ...current };
+                /*
+                 * FNXC:ProjectModelsWorkflowLanes 2026-07-02-13:30:
+                 * The registered Settings saver can resolve after workflow lane dropdowns changed again. Clear only snapshot-matching keys so Project Models follows the same no-lost-pending-edits invariant as Workflow Settings Values.
+                 */
+                for (const key of savedKeys) {
+                    if (workflowPendingValueEquals(current[key], pendingSnapshot[key]))
+                        delete next[key];
+                }
+                return next;
+            });
             setWorkflowRejections({});
         }
         catch (err) {