Membership Plugin is hiding non protected content

I have the installed membership plugin working fine on my site, but some content created by a forum plugin - Sofa Front Post - is being protected by the membership plugin. SFP doesn't create specific pages, so I can't add a page/s to the positive inclusion. And I've tried the URL Groups add, but obviously as people add to the Forum, those pages are not added to the positive list - what can I do please?