account.updatePushTarget gives AppwriteException document_already_exists

Future<void> setUserTarget(String? fcmToken, User user) async {
    if (fcmToken == null || fcmToken.isEmpty) {
      return;
    }
    try {
      final existingPushTarget = user.targets
          .where((target) => target.providerType == 'push')
          .firstOrNull;
      if (existingPushTarget == null) {
        // Create new target
        await _account.createPushTarget(
          targetId: ID.unique(),
          identifier: fcmToken,
          providerId: PROVIDER_ID,
        );
      } else if (existingPushTarget.identifier != fcmToken) {
        // Update existing target if token is different
        await _account.updatePushTarget(
          targetId: existingPushTarget.$id,
          identifier: fcmToken,
        );
      }
    } on AppwriteException catch (e, stackTrace) {
      if (kDebugMode) {
        print('Error setting user target: $e');
      }
      rethrow; // Rethrow to handle in calling code
    }
  }