diff --git a/packages/backend/src/queue/processors/InboxProcessorService.ts b/packages/backend/src/queue/processors/InboxProcessorService.ts
index 260ebe0d4000514346dfc9d66321beb31337aea2..5411eb69d03501722402a8fb3eb34ccd6a11adc2 100644
--- a/packages/backend/src/queue/processors/InboxProcessorService.ts
+++ b/packages/backend/src/queue/processors/InboxProcessorService.ts
@@ -194,7 +194,8 @@ export class InboxProcessorService implements OnApplicationShutdown {
 				throw new Bull.UnrecoverableError(`skip: signerHost(${signerHost}) !== activity.id host(${activityIdHost}`);
 			}
 		} else {
-			throw new Bull.UnrecoverableError('skip: activity id is not a string');
+			// Activity ID should only be string or undefined.
+			delete activity.id;
 		}
 
 		// Update stats