Hello,
We have implemented CallKit in our application to make voip calls. In our user investigations, we saw that some of our users have a strange timeline. The user makes one or two successful voip calls. So it seems our pushkit and callkit integrations are correct.
But after these few successful calls, the user doesn't get any other voip pushes for the recent calls. We are certain of that because we send an ack to our backend after the client receives the voip push. But the user doesn't send "push_received" ack to our backend for days.
Apple seems to return 200 after the voip push released from our backend, so no error on that side.
We have verified that the user has a valid voip token and doesn't remove the application. Because we can see recent API calls from the client to our backend in our logs, user is still using the app.
Does anybody have any suggestions? We are out of ideas really.