Hi! Welcome to the Samsung Members community!
Did you happen to use a screen protector before? To my knowledge, using one and then not using one can cause some odd issues.
I would contact Samsung directly to see if this is something they can repair, as that normally happens due to a coating on your phone wearing off.
The option I would suggest is to get a screen protector—not the most ideal method, but it will work. Even if it is a thin film.
Or
You can buy Oleophobic Coatings online and apply yourself- very cheap and just a spray