No Service after iPhone Overheats

Background: I use a 6ft charger from Amazon that has done well for months. Last night my phone was stuck underneath my pillow and got very hot to the touch. There was no overheating warning like you would get on a hot summer day. I noticed later that I have no service.

iPhone is running iOS 14.4, AT&T service is active. Is it possible the cellular modem has failed due to heat? If so does apple make such repairs?

I have already tried:

1. taking out the sim and reinserting
2. reset network settings
3. update carrier settings
4. check for update
5. power off and on phone

Thanks in advance..