Not surprising. Significant updates especially to the DE or systemd can cause this which is why some distros default to installing updates on reboot.
penny-farthing Another observation: although I use the Pocillo-dark style, the Discover window appeared with a white background; after this update, Discover now displays with a black background and a smaller font:
As was pointed out I added a patch to Discover from upstream which makes it obey dark theme on systems not using Plasma, this code is not due to be in a release for several months but since we are defaulting to Discover on Budgie and XFCE I figured not obeying dark theme was a significant issue that should be addressed sooner if possible.
Reality is it is highly unlikely that Qt apps will ever perfectly fit theming on gtk DE (Gnome, Budgie, XFCE) just as gtk apps don't on Plasma. From reading an issue a long time ago it seems Gnome devs are of the opinion that Qt apps should stand out as different... So as long as it obeys light/dark for these users, I am happy.
penny-farthing I would like to know if the arrival of Solseek (congratulations to Original-Syn) changes the choice of installing Discover on KDE Plasma, Budgie, and XFCE, and Gnome Software on Gnome? Or should we still keep Solseek and Discover/Gnome Software because they are complementary?
You can do whatever you want. But Discover or Gnome software will remain the OS provided defaults and recommendation. However it should be known that solseek does not currently have a notification mechanism to alert people of available updates.
Not actually the issue. No one encountered any of these issues and I am still unable to reproduce any of it across multiple different systems and VMs.