Why isn't the Paid Subscription Additional Usergroup applied?

[Snowhog]

This member purchased a Paid Subscription (Paid Subscription Level V) on November 12, 2025. The Additional Usergroups Paid Suscription Level V hasn't been marked by the system, although the Paid Subscription is identified in User Manager. Why does this happen? I can manually mark Paid Subscription Level V, but I shouldn't have to do that.

What do I look for? What causes this to happen?

[Snowhog]

Well, now it has been applied by the system.

Prior to today, the user had made only two posts. We don't promote into the Established Usergroup if a user has less than three posts. So something about being in the Registered Usergroup (post count less than 3) prevents a Paid Subsciption Additional Usergroup being applied, even though a Paid Subscription gets purchased? Why?