Its doing the annoying thing where its profile overrides FFZ and scroll locks chat to 1 line. I have recreated on Opera and Firefox. all I do is download your crappy extension. Normally Id reserve judgement till after contacting support but this has ben an issue for YEARS
#new (broken chat) submission
noble shard
pallid fulcrum
You can manually change it, No idea what causes it to it being set to 1 for some people
If you have a way to recreate it then you can share 
noble shard
I just download the FFZ extension and 7tv with default settings on an otherwise unmodified Opera, Firefox. n matter whaat I enter the 7tv 1 that is greyed out takes precedent. Even rearranging the profile order. Did nothing, I have to delete the profile but it gets recreated almost immediately