This topic is intended less an error report and more as a guide for people experiencing the same issues as I did, because I did not find anything related anywhere on the internet.
After upgrading to 24.04 I have noticed weird freezes in applications that use GTK. Since I am using Plasma desktop, the first applications to show these were Firefox and Thunderbird. The freezes would happen whenever a context menu (right-click), or a dopdown menu was opened and lasted for minutes, essentially rendering the applications unusable. Later I realized that all unity-related components, like lightdm and the unity desktop were affected as well.
After many hours of investigation, I found out that the problem was that the pulseaudio.service did not properly start, as it was somehow blocked by the pipewire-pulse.service that seemed to be some remnant of a previous pre-update configuration experiment.
I am still puzzled why the absence of the pulseaudio service would trigger such a peculiar malfunction, but after manually removing all the pipewire-pulse.service links in /etc/systemd/ everything worked fine again.
TLDR:
- After update
pipewire-pulse.serviceblockedpulseaudio.service - Missing
pulseaudio.servicetriggers weird freezes in GTK context menus. - Removeing
pipewire-pulse.servidefrom/etc/systemdsolved the problem.