My phone keeps going to lock screen even while I am on a call. I have it to ‘never’ auto lock.

[jkjb]

As above my Apple 6 keeps going to lock screen while I am using it. I had it set for five minutes and changed to never. Still happening.
I have reset it 5 times now. Any tips?

 

[jkjb]

MERGED QUESTION
Question from jkjb : "Keeps going to lock screen during use."

Apple 6 keeps going to lock after a minute. Had it set to auto lock at 5 minutes. Changed it to never. Still happening. I have reset the phone more than 8 times.

 

[jim_henry]

This sounds like what I experienced with a brand new iPhone 8 Plus. I went to the Apple store and they upgraded me to iOS 11.2 and that made the problem go away.