Previous font scaling retained in server-side decorations after switching HIDPI scaling off
I'm using mutter 40.3 and gnome-shell 40.3 on a fully-updated Arch Linux, under xorg.
If I switch HIDPI scaling to 200% and then back to 100% in the GNOME settings "displays" dialog, windows with server-side decorations retain upscaled fonts in their title bars:
This is true both of windows that were open at the time HIDPI scaling was turned off, and also of newly opened windows thereafter.
Restarting gnome-shell with "alt-f2 r" restores correct font scaling.
I'm unsure under what conditions this issue occurs - it may or may not depend on putting the computer to sleep with an external monitor plugged in at 200% scaling, and then waking it without that monitor plugged in. I do a lot of switching between monitors like this so it may be a factor - I don't think I see the problem all the time.