There are two user groups on my forum that a member can upgrade to given their activity. I've set up user groups looking up this suggestion here. So the secondary user group is where the user is added.
Right now, when the user meets certain requirements he is added to user group A. And when he meets another threshold he is added to user group B. And when I look up the user setting page he is added to user group A and user group B.
Theoretically, that shouldn't be a problem since I've set the "Display Styling Priority" but what happens is the users rank rolls back to default and after a while jumps between A and B and again back to default user group
I don't know why this is happening, I believe my setting are correct.