Windows stop repainting when another window is opened and Windows scaling is not 100%

[Toddler-Boy]

I think it might be related to this thread regarding a change in the paint-logic. Some weird WM_PAINT queue bug that sometimes leaves the whole window white and shows how delayed some repaints happen. I could imagine that something is blocking the main thread:

Resizing is strangely broken on Windows

You pull the window bigger and then smaller, but there is serious lag, the window is smaller but the contents inside are still getting bigger and vice verse. There is a disconnect between resizing and redrawing. Also, it flickers white and sometimes stays white. [flicker]