I hope this isn't an intended action. I remember long ago when you deleted posts, it was an immediate soft-delete and nobody else could see the contents while in the same topic. You didn't have to refresh. Could be a bug.
I've tried to load my forum with port 8000 (http://*.rhcloud.com:8000) and then in category permissions groups are shown properly. I'll use http://myhost.rhcloud.com:8000 when want to set category permissions.