In my case, the extension that was the "Global Menu Bar integration 3.5.4", which integrates the FF menu to the Unity panel. When I disabled it and restarted the FF, the "always on top" problem was solved.
Probably some integration to Unity no longer works, but for now it's ok for me.
Hi, I had the same problem and I solved finding the problematic extension/plugin.
First I used this: support. mozilla. org/en- US/questions/ 924733
http://
In my case, the extension that was the "Global Menu Bar integration 3.5.4", which integrates the FF menu to the Unity panel. When I disabled it and restarted the FF, the "always on top" problem was solved.
Probably some integration to Unity no longer works, but for now it's ok for me.