T I have problems with my screen when I clean it and wet it, there's a small part of the screen that looks like it repels liquid, but it's a small part, I don't know why that is.
What are you using to clean your screen? If there is a part of it which is repelling water, sounds like something oily got on that part and has gotten stuck onto the screen.
With wipes to clean screens but only seen when I clean it with something wet but when I clean it with something dry you see nothing.