Adding this plugin breaks systray

On a recent installation of Linux Lite 6.0 I added xfce-4-cpugraph-plugin. After adding it to the panel (I configured it to only show cpu bars, no graph), from the next reboot/login into xfce all icons from the systray plugin disappear. Removing and adding the tray plugin or deleting ~/.cache solves the problem for one login. After that they disappear again at the next login.

When removing xfce4-cpugraph-plugin from the panel, everything is fine again, so I guess that's the culprit.

apt-cache policy xfce4-cpugraph-plugin xfce4-cpugraph-plugin: Installiert: 1.2.6-1

apt-cache policy xfce4-panel xfce4-panel: Installiert: 4.16.3-1