Is anyone else experiencing inconsistent push notification deliverability? Specifically, I have a chat app where, when a user hits the send button, it triggers a push notification to the recipient user. This is handled via the FlutterFlow push notification cloud function.
Up until recently, I had no issues, but I recently redeployed the function and since then notifications are inconsistently delivered. The recipient may receive a push notification 1 out of 5 times (sometimes more, sometimes less), but it's very inconsistent. Sometimes the num_sent value is 0, and the recipient doesn’t receive the push notification. Other times, num_sent is 1 or greater, and the recipient successfully receives the notification.
This inconsistency ONLY occurs when notifications are triggered through the app. When sending push notifications through the Firebase console directly, they are always delivered with num_sent = 1.
Note, this is all tested with the app in the background or in a closed state, I'm aware that FCM doesn't work in the foreground for FlutterFlow. Additionally, FCM tokens have been checked and are valid, so I don't believe that's the issue either.
Is anyone else encountering this issue, and are there any known solutions?