Tor has never been officially supported by Kee but since they claim compatibility with Firefox extensions, we’d expect it to work for the most part.
I’m happy to accept code contributions via GitHub to re-enable support if the browser has made some kind of breaking compatibility change compared to Firefox in recent weeks.
I don’t know if anyone else uses Tor but perhaps someone will offer some more information soon.
Also, make sure you’ve followed all the usual troubleshooting advice in case your problem is nothing to do with Tor.