This particular model of Samsung is faulty. I had a samsung A7 2016. I got the screen replaced under warranty, and was still facing the issue again after a few days. Even my friend had the same problem. I think it's a manufacturing defect and Samsung...

stop others from buying this phone

it's not worth it,trust me. I'm highly disappointed.

i have the same issue even after I replaced the screen. i would advice you to not replace,rather go for a new one