This rather seems to be a machine-specific misconfiguration, maybe caused by the update from bookworm to trixie. Updates are shown as expected by package-update-indicator in a freshly installed trixie with Xfce on another computer.
- Bug#1111838: package-update-indicator: doesn't show upda... Olaf
- Bug#1111838: package-update-indicator: doesn't show... Guido Berhoerster
- Bug#1111838: package-update-indicator: doesn't show... Guido Berhoerster
- Bug#1111838: package-update-indicator: doesn't ... Olaf Jönsson

