[Q] Capacitive keys and Screen off

[LeParkour012]

New to a Samsung device or tablet in this case. I have a problem where I can't use the keys down below (including the home button). I also face random screen off. Hard to explain but it usually happens when the device moves away from me. Sometimes it's just random even when it doesn't move away. I don't know. Any help?

Edit: Everything in Smart Screen is disabled