White haze?!?!

[macbook123]

I've had this problem for a few weeks and wonder if others have experienced it too. Sometimes there's a white haze across my screen, i.e., contrast is decreased and everything's like behind a fog. It happens especially after I unplug an external monitor, but sometimes also randomly. It's quite noticeable.

 

[Sanpete]

There have been a couple other reports of this. Don't recall how it was resolved, but it's a known thing.