On my Android app using Firebase Cloud Messaging, I have found an issue with subscribing to topics when using multiple senders in my google-services.json file.
I get the following error after calling FirebaseMessaging.getInstance().subscribeToTopic("news")
:
FirebaseInstanceId: background sync failed: INVALID_PARAMETERS, retry in 10s
If I remove all but one sender from my google-services.json file, I am able to successfully subscribe to a topic and see them sync:
FirebaseInstanceId: topic sync succeeded
I am then able to send topic messages to this app, but then of course I am not able to receive messages from more than one sender.
I have set up the multiple senders in my google-services.json file as per the advice found here on stack overflow (How to put multiple project_number/sender id in google-services.json) and on Google's site (https://developers.google.com/android/guides/google-services-plugin#processing_the_json_file). I've been successfully sending messages to specific registration tokens from multiple sender ids without any trouble up until now. The issue seems to just be with subscribing to topics.
Is there a way to get topic subscription working with multiple senders?