This addon is getting worse and worse... I don't know why the dev is wasting his time on these stupid workarounds for the tab hiding issue.... Firefox added the ability to hide tabs weeks ago, stop fucking around with these idiotic workarounds and implement it properly. These idiotic workarounds are just making the plugin do some really erratic shit. For example: https://i.imgur.com/7oWdnuj.png

I did not create a single one of those groups. So now in addition to randomly creating groups (which it started doing a week go or so), now it seems to be populating some of them with tabs from sessions that ended a long time ago. I did not have those 86 or 116 tabs open the last time I closed Firefox. There are even duplicates in those two groups... I don't know where or how the fuck this addon decided to create those groups and populate them with tabs that I closed days ago, but there you have it...

You should go back to how you had the addon 3-4 weeks ago, and then focus only on writing in the tab hiding functionality. All this crazy shit you're trying to do with closing tabs and then reloading them with the moz-extension bullshit is not working at all, and it was a pretty stupid workaround to begin with.