diff --git a/packages/engine/src/merger-ai.ts b/packages/engine/src/merger-ai.ts
index 306a426d87..fa33c041d3 100644
--- a/packages/engine/src/merger-ai.ts
+++ b/packages/engine/src/merger-ai.ts
@@ -1222,10 +1222,28 @@ export async function landWorkspaceTask(
     // it so a retry never re-advances the ref. This makes a re-run after a partial
     // land idempotent for the already-landed repos.
     if (await isRepoLanded(repoRootDir, integrationBranch, entry.landedSha, taskId, entry.branch)) {
-      await log(`AI merge (workspace): sub-repo ${repoRel} already landed (${short(entry.landedSha!)} ⊑ ${integrationBranch}) — skipping`);
+      /*
+      FNXC:Workspace 2026-07-07-08:35 (Phase C A1 recovery — recover landedSha for finalize proof):
+      isRepoLanded's A1 trailer-fallback can prove a sub-repo is landed even when its landedSha
+      was never persisted (the persist-after-advance window in persistRepoLandedSha threw). That
+      left the in-memory result with landedSha: undefined, so finalizeWorkspaceTask's
+      `status === "landed" && landedSha` filter dropped the recovered repo, `anyLanded` stayed
+      false, and the proven repo's retry STRANDED the task in-review with missing-merge-confirmation
+      (finalizeTask's hasDurableMergeProof needs mergeConfirmed). Recover the CURRENT integration
+      tip as landedSha — the trailer-fallback already proved the task branch is an ancestor of this
+      tip — so the finalize builds durable mergeConfirmed proof and the A1 retry completes to done.
+      */
+      let recoveredLandedSha = entry.landedSha;
+      if (!recoveredLandedSha) {
+        recoveredLandedSha = await git(
+          ["rev-parse", "--verify", `refs/heads/${integrationBranch}`],
+          repoRootDir,
+        ).catch(() => undefined);
+      }
+      await log(`AI merge (workspace): sub-repo ${repoRel} already landed (${short(recoveredLandedSha ?? "?")} ⊑ ${integrationBranch}) — skipping`);
       repos.push({
         repo: repoRel, repoRootDir, integrationBranch, branch: entry.branch,
-        status: "landed", landedSha: entry.landedSha, alreadyLanded: true,
+        status: "landed", landedSha: recoveredLandedSha, alreadyLanded: true,
       });
       continue;
     }
diff --git a/packages/engine/src/worktree-acquisition.ts b/packages/engine/src/worktree-acquisition.ts
index e0bda12776..dd4ed98775 100644
--- a/packages/engine/src/worktree-acquisition.ts
+++ b/packages/engine/src/worktree-acquisition.ts
@@ -862,7 +862,15 @@ export async function acquireWorkspaceRepoWorktree(
       task: { ...task, worktree: undefined, branch: undefined },
       rootDir: repoAbsPath,
       store,
-      settings,
+      // FNXC:Workspace 2026-07-07-08:40 (FN-7360 regression — strip shared branch overrides for per-repo start-point):
+      // FN-7360 pinned fresh task worktree creation to `resolveIntegrationBranch(rootDir, settings)`
+      // when no executionStartBranch is present, so new branches never inherit an ambient root HEAD.
+      // For a workspace sub-repo, `settings` carries the SHARED project integrationBranch/baseBranch;
+      // honoring it resolves a branch absent from this sub-repo and fails `git worktree add` with
+      // "invalid reference". Strip both overrides here so freshStartPoint falls through to this
+      // sub-repo's own origin/HEAD — matching the per-repo base-SHA capture below, which already
+      // resolves against stripped settings (F4/KTD3).
+      settings: { ...settings, integrationBranch: undefined, baseBranch: undefined },
       logger,
       secretsStore,
       audit,