my hierarchy looks like this:

Main Category

- sub forum 1

- sub forum 2

Second Category

- sub forum 3

- sub forum 4

- sub forum 5

Third Category

- sub forum 6

For whatever reason, If I attempt to open any of the sub forums under the second category, i get redirected back to the forum homepage. I can access sub forums under the main category just fine, but for whatever reason, I cant get to the second or even third category sub forums. I can even open the specific posts under those sub forums, but cant open the sub forum itself. 

any thoughts?