No caching plugins.
When we set up Wishlist and Simple Press, we couldn’t get the role and therefore the SP permissions to update when a subscriber changed member level. A few people had written plugins to support the integration but they didn’t work in full either. We got someone to write us a basic plugin that solved the problem, code attached in a text file below.
This might be a factor. I don’t know if WL/SP has moved on in terms of integration. Perhaps we don’t need it any more?
I also was looking at your help text on the page Forum > User Groups > Map Users to User Group, specifically the option ‘Users are limited to single usergroup membership’ which we have ticked. I didn’t understand it fully, but it mentions membership plugins and problems associated with this option:
“Please note that auto usergroup membership by WP role or by forum rank may conflict or overwrite any manual usergroup memberships (such as moderator) you may set if you have single usergroup membership set”
Is that the culprit?