iPhone 12 Pro camera and apps not working

MY IPHONE 12 PRO PROBLEM:

1. PHONE BLANK WHEN I SWITCH FROM PHOTO TO VIDEO. JUST HOME BUTTON APPEAR (ONCE)
2. WHEN I OPEN SOCIAL MEDIA (EX: IG, WS), THE SOCIAL MEDIA PAGE CLOSE AUTOMATICALLY (FEW TIMES)
3. WHEN I ON VIDEO CALL, MY CAMERA BLANK FOR 1-2 SECONDS (FEW TIMES)
4. WHEN I OTP FOR QUITE LONG, NO SOUND (FEW TIMES)

PLEASE ADVISE.

[Re-Titled by Moderator]