iPhone flickering when viewing contacts and screen goes black while on the phone

I have an iPhone 13 Pro running iOS 16.3. I am having two issues:

1) When viewing a contact, the screen kind of flickers....like it's reloading. Sometimes it does it 2-3 times, other times it does it 6-7 times.

2) When I am using the phone, I can't always see what is on the screen. For example, I pull the phone away from me ear to identify another incoming call or I am done with the call and pull the phone away from my ear to hang it up, but the screen is black. I swipe up, down, sideways, adjust the volume, etc...but the screen does not display anything.

I have updated the phone, turned it on/off on numerous occasions, but I am still having intermittent problems. Pretty frustrating. Any suggestions?