Installed and gave access for Private tabs.

Toolbar button / "badge" displays and tooltip comes up...

BUT there is no displayed tab count on either the badge or in the tooltips.

I have been trying to find a replacement for an existing tab counter addon that has a bigger font and both my current addon ('Tab Count Icon by lllusion3418') and all but one other one that I have tested have displayed tab counts so I don't think it's anything to do with my settings (not that I have anything too crazy to begin with).

Just spitballing but unless the addon is just outdated / busted for everyone, then I suspect maybe it is because I am on Linux. Seems weird though considering FF is cross-platform and most of the others worked..

In any case, this addon does not have a preferences section so I suspect I would not be able to customize things like font size, foregroud/background color, etc.

FF v89.0.2 on Fedora 33 Cinnamon