First post here... I've been using the Android version for a while now, and it has been remarkable. I got an iPhone and wanted to get the same experience on iPhone that I've been having with Android. That is definitely not happening. The app will not ring the phone if it is not in the foreground with the phone active. If it goes to sleep, or you switch apps, you aren't going to receive any calls from Linphone. There were no configurations that would allow that to happen, even with push notifications.
Seems this is not just an issue with Linphone but other iOS VOIP clients as well. I've spent several days trying to find a workaround.
Is there any plan to address this for iOS? In its current state, at least on IOS 15.6, Linphone is pretty unusable.