This bug was fixed in the package ubuntu-gnome-default-settings -
20.04.0
---
ubuntu-gnome-default-settings (20.04.0) focal; urgency=medium
* debian/vanilla-gnome-default-settings.gsettings-override
- Override Ubuntu theme settings for GDM
- Switch backgrounds to upstream
Hi,
Thanks for your bug report. This package was originally Ubuntu-Gnome default
settings and at that time contained a small selection of overrides we chose to
keep for that project.
It would probably worth reviewing the remaining overrides as a larger
collective and perhaps there are others
