More graphical glitches

## What Happened

Just today my install started showing some weird graphical glitches. Black stripes (on white-background apps) and white stripes (on black-background apps) showing in really specific situations. So far it has happened to me with the Wingpanel, Greeter, Flatpak apps and context menus.

## Steps to Reproduce

You can reproduce by scrolling really slow or fast through an application (or even the Apps Menu) or just execute any command with the terminal that shows really long output so it automatically scrolls the screen.

https://user-images.githubusercontent.com/86124825/133107619-c1c6cb62-965e-4176-b0ea-a38c0712faaa.mp4

https://user-images.githubusercontent.com/86124825/133107755-9b1c5494-7ba5-42e9-b543-ab00dbeec1c8.mp4

## Platform Information