diff --git a/packages/dashboard/src/__tests__/server.test.ts b/packages/dashboard/src/__tests__/server.test.ts
index 8fe8973763..7af5acf58a 100644
--- a/packages/dashboard/src/__tests__/server.test.ts
+++ b/packages/dashboard/src/__tests__/server.test.ts
@@ -1222,6 +1222,82 @@ describe("createServer health and headless mode", () => {
     vi.useRealTimers();
   });
 
+  // FNXC:ReliabilityHealth 2026-07-10-11:15:
+  // FUX-042 regression: reliability GET/reset must read/write the per-project store, not the shared root store.
+  // Enumerated surfaces: (1) GET with projectId reads project store, (2) GET without projectId falls back to root, (3) POST reset with projectId writes project store.
+  it("FUX-042: GET /api/health/reliability reads the project-scoped store, not the root store", async () => {
+    const rootStore = createMockStore({
+      getSettings: vi.fn().mockResolvedValue({ reliabilityStatsResetAt: "2026-01-01T00:00:00.000Z" }),
+      getRunAuditEvents: vi.fn().mockReturnValue([]),
+    });
+    const projectStore = createMockStore({
+      getSettings: vi.fn().mockResolvedValue({ reliabilityStatsResetAt: "2026-05-10T00:00:00.000Z" }),
+      getRunAuditEvents: vi.fn().mockReturnValue([]),
+    });
+    const getEngine = vi.fn((projectId: string) =>
+      projectId === "proj_a" ? { getTaskStore: vi.fn(() => projectStore) } : undefined,
+    );
+    const app = createServer(rootStore, {
+      engineManager: { getEngine } as unknown as import("@fusion/engine").ProjectEngineManager,
+    });
+
+    const res = await GET(app, "/api/health/reliability?projectId=proj_a");
+
+    expect(res.status).toBe(200);
+    expect((res.body as { resetAt: string }).resetAt).toBe("2026-05-10T00:00:00.000Z");
+    expect(projectStore.getSettings).toHaveBeenCalled();
+    expect(projectStore.getRunAuditEvents).toHaveBeenCalled();
+    expect(rootStore.getSettings).not.toHaveBeenCalled();
+    expect(rootStore.getRunAuditEvents).not.toHaveBeenCalled();
+  });
+
+  it("FUX-042: GET /api/health/reliability without projectId falls back to the root store", async () => {
+    const rootStore = createMockStore({
+      getSettings: vi.fn().mockResolvedValue({ reliabilityStatsResetAt: "2026-01-01T00:00:00.000Z" }),
+      getRunAuditEvents: vi.fn().mockReturnValue([]),
+    });
+    const projectStore = createMockStore({
+      getSettings: vi.fn().mockResolvedValue({ reliabilityStatsResetAt: "2026-05-10T00:00:00.000Z" }),
+      getRunAuditEvents: vi.fn().mockReturnValue([]),
+    });
+    const getEngine = vi.fn((projectId: string) =>
+      projectId === "proj_a" ? { getTaskStore: vi.fn(() => projectStore) } : undefined,
+    );
+    const app = createServer(rootStore, {
+      engineManager: { getEngine } as unknown as import("@fusion/engine").ProjectEngineManager,
+    });
+
+    const res = await GET(app, "/api/health/reliability");
+
+    expect(res.status).toBe(200);
+    expect((res.body as { resetAt: string }).resetAt).toBe("2026-01-01T00:00:00.000Z");
+    expect(rootStore.getSettings).toHaveBeenCalled();
+    expect(projectStore.getSettings).not.toHaveBeenCalled();
+  });
+
+  it("FUX-042: POST /api/health/reliability/reset writes the project-scoped store, not the root store", async () => {
+    vi.useFakeTimers();
+    vi.setSystemTime(new Date("2026-05-13T12:00:00.000Z"));
+
+    const rootStore = createMockStore({ updateSettings: vi.fn().mockResolvedValue({}) });
+    const projectStore = createMockStore({ updateSettings: vi.fn().mockResolvedValue({}) });
+    const getEngine = vi.fn((projectId: string) =>
+      projectId === "proj_a" ? { getTaskStore: vi.fn(() => projectStore) } : undefined,
+    );
+    const app = createServer(rootStore, {
+      engineManager: { getEngine } as unknown as import("@fusion/engine").ProjectEngineManager,
+    });
+
+    const res = await REQUEST(app, "POST", "/api/health/reliability/reset?projectId=proj_a");
+
+    expect(res.status).toBe(200);
+    expect(res.body).toEqual({ resetAt: "2026-05-13T12:00:00.000Z" });
+    expect(projectStore.updateSettings).toHaveBeenCalledWith({ reliabilityStatsResetAt: "2026-05-13T12:00:00.000Z" });
+    expect(rootStore.updateSettings).not.toHaveBeenCalled();
+
+    vi.useRealTimers();
+  });
+
   it("rejects invalid windowDays values", async () => {
     const app = createServer(createMockStore({
       getActivityLog: vi.fn().mockResolvedValue([]),
diff --git a/packages/dashboard/src/server.ts b/packages/dashboard/src/server.ts
index 2a783ba560..1572eb6844 100644
--- a/packages/dashboard/src/server.ts
+++ b/packages/dashboard/src/server.ts
@@ -1654,7 +1654,19 @@ export function createServer(store: TaskStore, options?: ServerOptions): ReturnT
 
   app.get("/api/health/reliability", async (req, res) => {
     const projectId = getProjectIdFromRequest(req);
-    const scopedStore = projectId ? await getScopedStore(projectId) : store;
+    /*
+    FNXC:ReliabilityHealth 2026-07-10-11:15:
+    Reliability GET/reset must read/write the per-project store so multi-project servers report per-project stats.
+    Use the in-scope resolveProjectScopedStore helper (createServer scope) — NOT the badge-websocket getScopedStore, which lives in a different function and is not visible here.
+    Store creation can fail (getOrCreateProjectStore throwing on a DB error); mirror the project SSE handler and return a targeted 500 instead of letting the failure fall through to the generic Express error handler with a vague message.
+    */
+    let scopedStore: TaskStore;
+    try {
+      scopedStore = await resolveProjectScopedStore(projectId);
+    } catch (err: unknown) {
+      sendErrorResponse(res, 500, err instanceof Error ? err.message : "Failed to resolve project store");
+      return;
+    }
     const rawWindowDays = req.query.windowDays;
     const parsedWindowDays = rawWindowDays === undefined ? 7 : Number.parseInt(String(rawWindowDays), 10);
 
@@ -1760,7 +1772,17 @@ export function createServer(store: TaskStore, options?: ServerOptions): ReturnT
 
   app.post("/api/health/reliability/reset", async (req, res) => {
     const projectId = getProjectIdFromRequest(req);
-    const scopedStore = projectId ? await getScopedStore(projectId) : store;
+    /*
+    FNXC:ReliabilityHealth 2026-07-10-11:15:
+    Same in-scope resolveProjectScopedStore + guard as the GET handler so the reset writes reliabilityStatsResetAt to the per-project store and a store-creation failure returns a targeted 500 rather than a vague generic error.
+    */
+    let scopedStore: TaskStore;
+    try {
+      scopedStore = await resolveProjectScopedStore(projectId);
+    } catch (err: unknown) {
+      sendErrorResponse(res, 500, err instanceof Error ? err.message : "Failed to resolve project store");
+      return;
+    }
     const resetAt = new Date().toISOString();
     await scopedStore.updateSettings({ reliabilityStatsResetAt: resetAt });
     res.json({ resetAt });