Mutter shadow glitch
I am on Fedora 30 with gnome-shell 3.32.2-2.fc30 and mutter 3.32.2-1.fc30. With this version of Mutter there is a bug with some newly launched programs. Everytime I open Firefox, I get this weird/harsh shadow at the right and bottom side of the window. This also happens with pavu control program. In that case the shadow flickers a lot.
After interacting with the window (resizing, moving, maximizing) or switching workspaces or going to activities brings the shadow back to normal.
I am on a completly stock/vanilla Gnome. See mutter_shadow_bugmp4-2019-06-07_17.31.56 video for an example of the bug.
This happens on X11 and Wayland.