I've been writing about this problem for the last year, I haven't figured it myself and I tried nearly everything.
When I receive a call, there is like 33 % chance my phone will not ring. Or otherwise, it will start ring but after 1-2 seconds the ringtone cuts off.
Here's a video I recorded myself:https://youtu.be/gbI8FriHJxI
No matter what kind of call it's (phone call, whatsapp, skype, messenger), your melody will cut off after 2 seconds. I approximatelly miss every third call.
Well, this part is most interesting. The problem first occured more than an year ago on my iPhone 12 pro. I bought 14 pro max later and the problem persisted. I bought another 14 pro max and I still have this problem.
To be clear, I reinstalled system 3 times, I created new Apple ID to avoid the problem is on my iCloud. I turned all possible settings off. I still haven't figured where is the culprit.
But! I noticed one thing. I am able to receive nearly all calls when I don't download any apps from App store. I also have to close all my background apps regularly (once or twice per day).
Second interesting thing: The problem doesn not occur on iPhone 7. I tried to replicate this issue on my old iPhone but althought I was trying so hard I haven't replicated it.
To make it clear, there is more of us having this problem but somehow we are not able to create one big topic to let Apple know about this...
Either it's something with front camera which cuts off the ringtone or it's 3rd party app. I have no idea. I turned attention awareness off and true depth camera off. I tried to turn every possible thing off in settings. I am lost at this point and only solution left for me is to switch to android.