Constantly occurring problem in video calls

Good evening, i am constantly occurring a problem in whtspp video call instagram video call and other 3 rd party apps after my software update..i also did the delete app and download again procedure but after few days the problem occur again..ex-whenever i do a video chat to anyone after few seconds the call answerd by other person automatically get disconnected and the other problem is whenever i am on video chat after few seconds the screen will automatically get dim i changed the screen timeout setting but that doesn’t work…so I request you to please help me in this

Thankyou