Display blinks and I can't hang up a call


first thank you for your help.

I have the problem that I can’t hang up a call. If I want to hang up a call the display starts blinking and although I can see (and press) button to hang up nothing happens. Sometimes I have the same problem by try calling and hang up too.

I can only stop by restarting PF or by killing the phone app.

Until now I tried to clear phone app data and to restart phone.

Do you have an idea to resolve my problem?

A few minutes ago I had the same problem, but I found out why it happend by me:
After 2 minutes of call (and inactivity on the display) the display locked the screen.
So I should unlock the display (with the password) to hang up the call.
But there’s a little work-around: With a short press on the power-button you can hang up a call without needing the display.

I will look for a tool that blocks the lockscreen while a call is active.

Best regards