I will guarantee it works with Fedora 33. I'm using it right now. Make sure it's actually installing the correct version of Tools because it does not delete the old one and for some stupid reason the install process uses the first one listed in an alphanumeric search (yeah, I know... it's dumb). Delete any old version of parallels-tools from /usr/src/ EXCEPT parallel-tools-18.104.22.168183. Then try to reinstall.