Kee icon greyed out

Hi everyone,

I have an issue similar to this post :
Greyed kee icon and blank option page after installing kee extension.
But for me cleaning Firefox profile multiple times didn’t helped nor uninstalling/installing Firefox.
I’m on a multiuser machine in a domain and I have no issue on other user’s profile, just this one. Kee is working fine on Edge for this problematic user.

Any idea of what’s going on here ?
How can I troobleshoot further ?