So normally push notifications work correctly. I have registered our rocket.chat instance with the cloud, and both test push notification as well as regular notifications for messages work as expected.
However we are experiencing the issue with some users, that after their Android apps have been closed for some time, they will no longer receive push notifications.
Trying to send a test push notification then raises the error:
There are no tokens for this user [error-no-tokens-for-this-user]
Then the issue is resolved as soon as the user opens the app again, push notifications work again normally.
This creates the awkward situation where users need to periodically open the app to check for messages manually, making push notifications useless…