Oh man that sucks! I owned all the 12’s this year but returned all but the 12 mini and the 12 Pro Max. They’re okay on 4G. But the regular 12 that I had and returned often would randomly heat up. At that point I had made up my mind to go for a mini anyway for my main line. My 12 Pro Max is being used kind of like I used to use my iPad mini.
I have a Samsung S20 with the same 5G modem. It does give me better call clarity than my iPhone 12 mini or 12 Pro Max does, but I kept this phone on 4G service, too. I’m not sure why my Samsung phones and some of the other Android phones I’ve had give me more clear voice calls than I can get with iPhones.
I suspect Samsung may have a better antenna design. One of the reasons I have two lines in the first place is I could only count on my Android phones for actual good voice calls. I’ve had problems with either iPhone mics and/or intel modems. Given that I was dealing with elder care and medical emergencies on a regular basis I had to keep one good voice phone, even though I usually preferred iOS for most other things.
I’m probably keeping the 12 Pro Max for 2 years, but will likely upgrade the mini this year.
Thanks for sharing your experiences with your phone. It was very informative, thank you.