Ah, the window. Yeah, I remember that now. Probably got so used to it that I didn't even think of it... but I also remember thinking that I didn't see it before (this thinking being years ago). Probably just a false memory (or a different world). Curiously enough, as I go look at it right now, it looks just fine no matter the angle.

I think I now also remember the watery areas at Beaucedine showing the issue, though right now they too seem quite fine to me. I can still see a little bit of a battle around where the water meets the ground, but not quite as I remembered it. Could be regression in Wine, though I also did recently switch from NVIDIA to AMD in the graphics department, so hmmm... got some testing to do.