I'm wondering if you might have forums allowed on more than one quota. To double check that:
If you go to your "Profiles" module, one of the "Tools" there is called Quota Compare (to compare Modules allowed in each profile quota). It's url is found at: https://(yoursite).com/profile/quota_compare
If you go there to Quota Compare tool, you can see if the "Forum" module (under the Profiles heading) is activated for more than one quota or just active for one quota such as Master Admin. On my site, I created a separate quota called "Forums" and made it the only quota with an active Forum module- which is the forum for my whole site to use. Then I created a new profile as a 'child' of my master admin user and named it Forums, and put that as the only member of my Forums Quota... thus the only member of my site that can have a forum and forum categories.
I say this because you may have activated forums for various quotas on your site, for example for all regular members. You can see whether you did in the Quota Compare tool. That would explain why you might have set the categories in a certain order on your own profile forums, only to see them in a different order somewhere else. Check that first. Perhaps it was your intention to let all members have their own individual forums on your site, but most people prefer one site-wide forum, so I'm suggesting you first check to see how many users you have allowed to have forums.
To set which quotas are allowed to have forums (and categories), you would go into your Forum module 'quota config' tab, here: https://(yoursite).com/forum/admin/quota and set each selected quota with the 'allow profile forum' checkbox on or off. On my site the only quota I have the checkbox checked on is my Forums Quota.
Hope this helps... and I apologize if it's not what you were asking about at all!
But it's always handy to know where to find the Quota Compare tool, in any case!
...just another satisfied Jamroom customer.
Migrated from Ning to Jamroom June 2015
updated by @strumelia: 20 Apr 2019 08:49:55AM