BuddyPress Rules and negative rules don't seem to work

I am developing a basic community site using the Klein theme for Wordpress, BuddyPress and Membership Pro.

It has three subscription levels: "Base Entry Level" for casual visitors to the site "Free Level" for users who are registered but have not paid and "Subscribed level" for users who have paid. I would like to block access to friending and messaging for the middle level.

I have two subscription plans "Free" and "Annual". "Free" has one level ie "Free Level" and "Annual" has one level ie "Subscribed Level"

The negative rules seem to work fine if I block access to a page or a menu item so I'm fairly confident that the subscription levels/plans are working - it just doesn't like buddypress rules. I have also tried URL groups as suggested in another thread https://premium.wpmudev.org/forums/topic/membership-plugin-update-now-means-things-that-are-negatively-protected-still-show and that didn't work - I just got an error message.

I'm finding that a lot of the support material out there is for old versions of the plugin which doesn't help me trying to figure out where the problem is.

I would be really grateful if someone could give me a steer on this as I have spent days trying to get the thing to work. Many thanks