iPhone (14 pro max) doesn’t ring when apps are open

As title says, my iPhone will not ring when certain apps are open. I made a lot of test to find the culprit but I ended up uninstalling them all. When I have only Apple native apps, my iPhone rings well. If I start downloading any new apps (from app store), my iPhone will stop ringing on incoming calls (not on every call, I miss every 2nd or 3rd). Don’t know why.

At first I thought the culprit is keyboard app Swiftkey. My iPhones was ringing for a week when I removed this app but it stopped ringing once again. I found out that YouTube was on the blame this time. It was probably stuck in the background so I closed the app and my phone started ringing again.

I need some help. I feel like iOS can’t handle those apps that were not made by Apple (Instagram, Facebook, YouTube, Netflix, HBO, Messenger, etc.) When I have only native Apple apps, my phone is working just fine, I miss no calls. But if I leave some of these apps (like YouTube, YouTube Music, Instagram, Twitter, Netflix) open in background, my phone will just sooner or later stop ringing on incaming calls.

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Btw, I have brand new iPhone 14 pro max. I also reinstalled the whole software, reseted all network setting and turned attention awareness feature off. This is 99% software issue. iOS is just not able to handle apps. I don’t know how is it possible they take over speaker to mute my ringtone when somebody is calling.