I am using tab groups and suddenly they all disappeared. There is no hint or trace of this function, not even in the tab pulldown menue. I checked the internet, I restartet Firefox several times, I restarted my notebook (Windows 11), I checked about:config (tab groups are enabled). I even reinstalled firefox - it seems like tab groups never have existed. What might have happend - and how could I get that feature back?

Thank you in advance Wolf