Dial phone, screen blanks -> can't hang up My Nokia 4.2 (Android One 9, security patch for December 5, 2019) is lately exhibiting a very weird behavior. If I dial a number, either using the keypad or from history or a contact, the screen blanks. I don't mean the autoblank when it's held to my face, I mean it goes black immediately. As a result, I can't hang up a call (or conference a third person, or anything). 

If I tap power ... nothing happens. If I hold it to my face and remove it ... nothing. If I hold Power down, the phone doesn't turn off. When the other person hangs up, the screen turns back on. Sometimes if I press Power repeatedly I can get the screen on. Sometimes not.

Of course, I can plug in earbuds and use the earbud button to hang up, but for a quick call I hate having to do that.

Otherwise the phone mostly works OK. No other obviously incorrect behavior.

Odd. Any suggestions will be greatly appreciated.
Please check if it happens in safe mode too:


If the problem is not resolved, factory-reset is next step.
If it is resolved, it implies one of the installed apps is the culprit. First step could be to remove all apps having telephony related permissions and then check. Add apps one by one and check. Painful process, yes, or go nuclear and factory reset after backing up your data.