Not sure if what you are calling a hard reset was in fact really a Forced Restart. Try the Forced Restart.
Follow the instructions very carefully, as this is a bit tricky. You may need to repeat this several times.
Force restart iPhone - Apple Support
There are only 2 possible results when you perform a Forced Restart:
1) The phone returns to normal operation
or
2) There is a hardware problem with the phone that will need attention at the Apple Store (make an appointment) or at an authorized Apple Service shop
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