Render window bugg

[vincent-studio3D]

Hello there!
I saw this weird bug and thought I'd report it, maybe it's allready known.
I was viewing a test render at 100%, and it jumps between a weird jagged version and a smooth version depending on where I pan the image. It's really no big deal and the final saved image is the smooth version. It did however lead to a few rerenders before I understood that the problem was "harmless".

It's the exact same image, I've just moved the image in the viewer a tiny bit.