Twitch is the same way, but youtube is working fine. Hexbear loaded correctly when I first installed this distro, then it just stopped working the next day without anything being changed.
I remember seeing someone else mention a similar problem a while back, but I couldn't find that post when I tried searching for it.
It sounds exactly like that. Perhaps you ran firefox as root at some point?
I'd say:
rm -rf .cache/mozilla
~/.mozilla
:chown -Rc $(id -u):$(id -g) ~/.mozilla
/.mozilla
:chmod -Rc u+w ~/.mozilla
If you get permissions errors, run them with sudo.
It was the firefox that came preinstalled in the distro and I only ever ran it from the icon on the panel, but someone else's advice to install the flatpack version worked so I just swapped to that. Thanks for taking the time to try to help, anyways.