Try this, inactivate all plugins you have that could be infecting this and only activate the one you are trying to fix and see which plugin could be infecting this bug. This is what I do sometimes it works sometimes it don't. 

Hi @iraarel,

Please note: karmarpgs is our active member, but not from the wpForo support team. Please send login details to info[at]gvectors.com email address. 

IraArel,

We'll check and back to you asap. 

I am using wpforo+buddypress and haven't experience any issue as such. I think you need to recheck all settings carefully if you are done with uninstalling plugins to verify the conflict.