7/4/20
I had a similar situation and the only fix that worked was to RESTORE my iPhone thru iTunes (it took quite a while to complete but since then my iPhone 6S is working quite well).
Read how on the Internet and hopefully you have a current backup of you iPhone on iCloud to use after the restore is finished. I didn’t and lost some data which took quite awhile to recreate. Since then l have set automatic Backup “ON” in my iPhone settings.
Good luck. It wasn’t a pleasant experience, but I finally got my phone working again (after many hours of frustration and lost contact with friends and the outside world).
Frank M
