Windows randomly become blurry when using HiDPI display and 200% scaling
I have an external HiDPI screen connected to my laptop (which also has a HiDPI screen, but is disabled). Sometimes, windows become blurry. There is no way to get them to be rendered sharply, other than to close the window and start it again (you'll have to zoom the image below to 100% to see the issue).
When I make a screenshot of the window only (Alt+PrScr), the screenshot is misplaced. This only happens with windows that are blurry, not sure if this is related somehow but it might help:
Feel free to reassign to a different component if this is not the right one. Mutter and gnome-shell 3.30.1-2 from Debian testing.