iPhone (14 PM) ringtone cutting off after 2 seconds

I have a curious problem that I have been dealing with for two years now...

Sometimes my iPhone rings for about 2 second and then goes completelly silent. You see a screen somebody is calling but there is no sound coming out of iPhone. The ringtone cut off after 2 seconds itself (turning off attention awareness feature doesn't help).

I've been dealing with this problem on iPhone 12 Pro and I have the same problem on 14 Pro Max. I've already done two factory resets and I also started a new iPhone from the scratch and still the problem is not resolved.

I've literally done all steps I could to resolve this... It gotta be software issue. Perhaps some app is causing it. I need your advices, perhaps you have the same problem.

I know one thing, it happens especially when your phone is face down or in your pocket (which means your front camera is covered but again turning off awareness feature doesn't help).