When i make a call on my lg g4c the screen goes blank until the call ends. if i want to end the call early i cant touch the screen as it doesnt cone on until the call has ended?
My partner had a similar problem. She got a new replacement phone, replaced the cheap glass screen protector and the fault returned after 24 hours!
I removed the cheap screen protector and all is perfect again.
Would be interested to know if you have a screen protector and if removing it also fixed your problem?