A repeated notification error is easier to investigate when the report separates the trigger from the display. State which action should create the notification, approximately when it happened, and whether it failed to arrive, arrived late, or displayed an error. Include the short visible error text and the app or browser version.
Try one safe comparison, such as another device or a test account if available, but avoid generating dozens of duplicate notifications. Include local time with timezone and whether the official service status mentions an incident. Remove message contents, recipients, account IDs, and tokens from screenshots. A concise timeline shows whether the problem is persistent or intermittent.