diff --git a/apps/frontend/src/renderer/hooks/useIpc.ts b/apps/frontend/src/renderer/hooks/useIpc.ts
index 1dab10bc5e..1ad2fea8e4 100644
--- a/apps/frontend/src/renderer/hooks/useIpc.ts
+++ b/apps/frontend/src/renderer/hooks/useIpc.ts
@@ -222,14 +222,18 @@ export function useIpcListeners(): void {
 
         // Sync roadmap feature when task completes
         if (status === 'done' || status === 'pr_created') {
-          useRoadmapStore.getState().markFeatureDoneBySpecId(taskId);
-          // Re-read state after mutation to get updated roadmap
+          // Use event's projectId (from callback param) — NOT the store's activeProjectId.
+          // During project switches, the store may hold a different project's roadmap.
+          const eventProjectId = projectId;
           const rm = useRoadmapStore.getState().roadmap;
-          const currentProjectId = useProjectStore.getState().activeProjectId || useProjectStore.getState().selectedProjectId;
-          if (rm && currentProjectId) {
-            window.electronAPI.saveRoadmap(currentProjectId, rm).catch((err) => {
-              console.error('[useIpc] Failed to persist roadmap after task completion:', err);
-            });
+          if (rm && eventProjectId && rm.projectId === eventProjectId) {
+            useRoadmapStore.getState().markFeatureDoneBySpecId(taskId);
+            const updatedRm = useRoadmapStore.getState().roadmap;
+            if (updatedRm && updatedRm.projectId === eventProjectId) {
+              window.electronAPI.saveRoadmap(eventProjectId, updatedRm).catch((err) => {
+                console.error('[useIpc] Failed to persist roadmap after task completion:', err);
+              });
+            }
           }
         }
       }
diff --git a/apps/frontend/src/renderer/stores/roadmap-store.ts b/apps/frontend/src/renderer/stores/roadmap-store.ts
index 05a9fce067..e93274744b 100644
--- a/apps/frontend/src/renderer/stores/roadmap-store.ts
+++ b/apps/frontend/src/renderer/stores/roadmap-store.ts
@@ -713,7 +713,9 @@ async function reconcileLinkedFeatures(projectId: string, roadmap: Roadmap): Pro
 
   if (hasChanges) {
     const updatedRoadmap = useRoadmapStore.getState().roadmap;
-    if (updatedRoadmap) {
+    // Guard: only save if the store still holds the same project's roadmap.
+    // A project switch during async reconciliation could replace the roadmap.
+    if (updatedRoadmap && updatedRoadmap.projectId === projectId) {
       console.log('[Roadmap] Reconciled linked features with task states');
       window.electronAPI.saveRoadmap(projectId, updatedRoadmap).catch((err) => {
         console.error('[Roadmap] Failed to save reconciled roadmap:', err);
@@ -729,6 +731,9 @@ export async function loadRoadmap(projectId: string): Promise<void> {
   // Always set current project ID first - this ensures event handlers
   // only process events for the currently viewed project
   store.setCurrentProjectId(projectId);
+  store.setRoadmap(null);  // Clear immediately to prevent stale cross-project saves
+  store.setCompetitorAnalysis(null);
+  store.setGenerationStatus({ phase: 'idle', progress: 0, message: '' });
 
   // Query if roadmap generation is currently running for this project
   // This restores the generation status when switching back to a project