I did a search through the KDE bug tracker, and it looks like someone reported the same root problem back in 2020:
https://bugs.kde.org/show_bug.cgi?id=423756 ** Bug watch added: KDE Bug Tracking System #423756 https://bugs.kde.org/show_bug.cgi?id=423756 -- You received this bug notification because you are a member of Kubuntu Bugs, which is subscribed to kio in Ubuntu. https://bugs.launchpad.net/bugs/2011806 Title: [lunar] Snaps don't launch due to cgroup issue To manage notifications about this bug go to: https://bugs.launchpad.net/gnome-shell/+bug/2011806/+subscriptions -- kubuntu-bugs mailing list kubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/kubuntu-bugs