Sudden app crashesWhile using sometimes mobile automatically comes to lock screen and need to unlock again.What to do?

Screen of my M20 starts flickering sometimes ,its very irritating ,please fix it.

My mobile screen starts flickering sometimes

Where have to send bug reports?

My device screen is sometimes ghosttapping it usually happens in toutube app ,while i am watching vedio it automatically loads comment,plays next vedio,opens previous app,it is so irritating ,what can i do?