Need some help with Buddypress Forum URLs

Hey, I'm moving a site from Joomla/Jomsocial to WordPress/Buddypress.

I'm getting the hang of it, however I can't seem to figure out why my forum urls aren't working. Basically I can get the the main forum page:

You can also get into SOME individual topics.

However if you try and drill into one of the specific forum pages or some other topics, they 404:

Any ideas? Anyone seen this before? I feel like they should either work or not work, but they're 50/50