Gnome extension 'system-monitor' not working

I want use the Gnome extension 'system-monitor' but it doesn't work or at least doesn't show up in the task bar.
I checked with a Manjaro system (Gnome 48) and there it works. I tried to deactivate the current extensions in Bazzite to see if something interferes but nothing did.
Any idea what could be the problem?
https://extensions.gnome.org/extension/6807/system-monitor/