I'm working on a second board for the first time and am runnig into a small problem. I added two forums, at least I thought so. But when unchecking "use as category" and saving to have a new forum, after beeing saved the checkbox is checked, so that I only can create categories, but not forums.

When I create a new forum for test reasons, it comes up with a unchecked checkbox. After saving it will be checked ... 

Caches are erased already, no change.

Where can I find the mistake? 

Thanks for caring, Bernd