FireFox Extension - Disable / Remove Weirdness

I use a LOT of FireFox extensions and in an attempt to slim my install down I disabled the less used ones so I could remove them in a week or so if I hadn’t needed them. The first stage was easy, right click the extensions in the Extensions menu and choose “disable”. I then carried on using FireFox as normal. I didn’t need the extensions removed immediately so I didn’t restart it.

A couple of days went past, the browser had been restarted a few times and I wasn’t missing any of the functionality. So I removed the extensions thinking all was well. Very foolish of me.

I first started to notice my tabs were acting a little different a couple of days later; after I’d removed the (previously disabled) extensions and restarted the browser. External applications were opening a new tab each time rather than replacing the right most one and other little bits like that. But this only started after the remove, not the disable - which is wrong.

I don’t know why, I’m assuming that something doesn’t understand “disable” and left the extensions running even though the GUI displayed them as greyed out. And then when I removed them it actually actioned the change. I’ve not (yet) been able to reproduce it and it’s bugged the heck out of me for almost ten whole minutes. I’m mentioning this in the hope that someone else has seen the same thing but actually managed to reproduce it or work out what’s wrong.