diff --git a/src/app/imex/sync/sync-wrapper.service.ts b/src/app/imex/sync/sync-wrapper.service.ts
index 4baa5e0fa9..5728e4900e 100644
--- a/src/app/imex/sync/sync-wrapper.service.ts
+++ b/src/app/imex/sync/sync-wrapper.service.ts
@@ -134,6 +134,14 @@ export class SyncWrapperService {
     return this._isSyncInProgress$.getValue();
   }
 
+  /**
+   * Returns true if an encryption operation (password change, enable/disable) is in progress.
+   * Used by ImmediateUploadService to avoid uploading during critical encryption operations.
+   */
+  get isEncryptionOperationInProgress(): boolean {
+    return this._isEncryptionOperationInProgress$.getValue();
+  }
+
   // Expose shared user input wait state for other services (e.g., SyncTriggerService)
   isWaitingForUserInput$ = this._userInputWaitState.isWaitingForUserInput$;
 
@@ -468,27 +476,34 @@ export class SyncWrapperService {
 
     SyncLog.log('SyncWrapperService: forceUpload called - uploading local state');
 
-    try {
-      const rawProvider = this._providerManager.getActiveProvider();
-      const syncCapableProvider =
-        await this._wrappedProvider.getOperationSyncCapable(rawProvider);
+    // Block parallel syncs during force upload to prevent them from trying to
+    // download/decrypt old data with a potentially different encryption key.
+    // This is critical when forceUpload is triggered after password change.
+    await this.runWithSyncBlocked(async () => {
+      try {
+        const rawProvider = this._providerManager.getActiveProvider();
+        const syncCapableProvider =
+          await this._wrappedProvider.getOperationSyncCapable(rawProvider);
 
-      if (!syncCapableProvider) {
-        SyncLog.warn('SyncWrapperService: Cannot force upload - provider not available');
-        return;
+        if (!syncCapableProvider) {
+          SyncLog.warn(
+            'SyncWrapperService: Cannot force upload - provider not available',
+          );
+          return;
+        }
+
+        await this._opLogSyncService.forceUploadLocalState(syncCapableProvider);
+        this._providerManager.setSyncStatus('IN_SYNC');
+        SyncLog.log('SyncWrapperService: Force upload complete');
+      } catch (error) {
+        SyncLog.err('SyncWrapperService: Force upload failed:', error);
+        const errStr = getSyncErrorStr(error);
+        this._snackService.open({
+          msg: errStr,
+          type: 'ERROR',
+        });
       }
-
-      await this._opLogSyncService.forceUploadLocalState(syncCapableProvider);
-      this._providerManager.setSyncStatus('IN_SYNC');
-      SyncLog.log('SyncWrapperService: Force upload complete');
-    } catch (error) {
-      SyncLog.err('SyncWrapperService: Force upload failed:', error);
-      const errStr = getSyncErrorStr(error);
-      this._snackService.open({
-        msg: errStr,
-        type: 'ERROR',
-      });
-    }
+    });
   }
 
   async configuredAuthForSyncProviderIfNecessary(
diff --git a/src/app/op-log/sync/immediate-upload.service.spec.ts b/src/app/op-log/sync/immediate-upload.service.spec.ts
index e1f9ee419b..9c0591cc13 100644
--- a/src/app/op-log/sync/immediate-upload.service.spec.ts
+++ b/src/app/op-log/sync/immediate-upload.service.spec.ts
@@ -5,6 +5,7 @@ import { OperationLogSyncService } from './operation-log-sync.service';
 import { ActionType, Operation, OpType } from '../core/operation.types';
 import { SyncProviderId } from '../sync-providers/provider.const';
 import { DataInitStateService } from '../../core/data-init/data-init-state.service';
+import { SyncWrapperService } from '../../imex/sync/sync-wrapper.service';
 import { BehaviorSubject } from 'rxjs';
 
 describe('ImmediateUploadService', () => {
@@ -12,6 +13,7 @@ describe('ImmediateUploadService', () => {
   let mockProviderManager: jasmine.SpyObj<SyncProviderManager>;
   let mockSyncService: jasmine.SpyObj<OperationLogSyncService>;
   let mockDataInitStateService: { isAllDataLoadedInitially$: BehaviorSubject<boolean> };
+  let mockSyncWrapperService: { isEncryptionOperationInProgress: boolean };
   let mockProvider: any;
 
   const createMockOp = (id: string): Operation => ({
@@ -59,12 +61,18 @@ describe('ImmediateUploadService', () => {
       isAllDataLoadedInitially$: new BehaviorSubject<boolean>(false),
     };
 
+    // Mock SyncWrapperService - default to no encryption operation in progress
+    mockSyncWrapperService = {
+      isEncryptionOperationInProgress: false,
+    };
+
     TestBed.configureTestingModule({
       providers: [
         ImmediateUploadService,
         { provide: SyncProviderManager, useValue: mockProviderManager },
         { provide: OperationLogSyncService, useValue: mockSyncService },
         { provide: DataInitStateService, useValue: mockDataInitStateService },
+        { provide: SyncWrapperService, useValue: mockSyncWrapperService },
       ],
     });
 
@@ -189,6 +197,25 @@ describe('ImmediateUploadService', () => {
       expect(mockSyncService.uploadPendingOps).not.toHaveBeenCalled();
     }));
 
+    it('should skip upload when encryption operation is in progress', fakeAsync(() => {
+      // Set encryption operation in progress (e.g., password change)
+      mockSyncWrapperService.isEncryptionOperationInProgress = true;
+      mockSyncService.uploadPendingOps.and.returnValue(
+        Promise.resolve({
+          uploadedCount: 1,
+          rejectedCount: 0,
+          piggybackedOps: [],
+          rejectedOps: [],
+        }),
+      );
+
+      service.initialize();
+      service.trigger();
+      tick(2100);
+
+      expect(mockSyncService.uploadPendingOps).not.toHaveBeenCalled();
+    }));
+
     it('should handle fresh client (syncService returns null)', fakeAsync(() => {
       // Fresh client handling is now done inside syncService.uploadPendingOps()
       // which returns null for fresh clients
diff --git a/src/app/op-log/sync/immediate-upload.service.ts b/src/app/op-log/sync/immediate-upload.service.ts
index 24a229b9eb..9c3f91a601 100644
--- a/src/app/op-log/sync/immediate-upload.service.ts
+++ b/src/app/op-log/sync/immediate-upload.service.ts
@@ -8,6 +8,7 @@ import { isFileBasedProvider, isOperationSyncCapable } from './operation-sync.ut
 import { OpLog } from '../../core/log';
 import { DataInitStateService } from '../../core/data-init/data-init-state.service';
 import { handleStorageQuotaError } from './sync-error-utils';
+import { SyncWrapperService } from '../../imex/sync/sync-wrapper.service';
 
 const IMMEDIATE_UPLOAD_DEBOUNCE_MS = 2000;
 
@@ -49,6 +50,7 @@ export class ImmediateUploadService implements OnDestroy {
   private _providerManager = inject(SyncProviderManager);
   private _syncService = inject(OperationLogSyncService);
   private _dataInitStateService = inject(DataInitStateService);
+  private _syncWrapper = inject(SyncWrapperService);
 
   private _uploadTrigger$ = new Subject<void>();
   private _subscription: Subscription | null = null;
@@ -123,6 +125,11 @@ export class ImmediateUploadService implements OnDestroy {
       return false;
     }
 
+    // Don't overlap with encryption operations (password change, enable/disable)
+    if (this._syncWrapper.isEncryptionOperationInProgress) {
+      return false;
+    }
+
     // Must have an active provider
     const provider = this._providerManager.getActiveProvider();
     if (!provider) {