Membership access levels with bug

Hi there, good morning.

I'm running a membership site with recorded webinars. Each month we have a workshop with 20 speakers, TED style. We record te speeches and put it online.
In february we did the first one, in march the second. Until november, we'll have 10 workshops, with 200 videos.

I have different subcribing options. Users can buy access to only one workshop/webinar, and have access to 20 videos. Or they can buy the whole package with access to all videos from all 10 workshops/webinars.

I'm using the membership plugin to restrict access. I'm posting the videos of each workshop as a post with embeded video in different categories.

The posts with videos from the first webinar are under the "workshop 1" category, the workshop 2 under "workshop 2" category, etc, The access levels "workshop 1" and "workshop 2" are working fine, but the "all 10 workshops" access level is not working.

The "all 10" access level is identical the other 2 access levels, only granting access to both categories.

When I sign as an user with "all 10 workshops" access level, the site doesn't allow me to accesse any content.

Any suggestions about what happening?

Thanks a lot, Miguel