I'm doing that now and it doesn't make a difference. Something broke in the browser so I'll either completely refresh it or update it.
What version are you running? I just tested with FF 151.0.3 with uBlock Origin and upvoting/downvoting worked.
I use FF 150 stable and I strip out as much as possible in the about:config. It just stopped working out of nowhere. I just downloaded Librewolf and the vote button is working like it should.
An easy way to check for settings issues is create a new profile. I also have mine with lots of crap turned off.