System not registered Error since Upgrade to RHEL 8.2

I have a free RHEL 8 Developer license for almost a year. This ends at the end of June. Yesterday I upgraded from RHEL 8.1 to RHEL 8.2. Since then I have received constant notifications, that my system is not registered and that I can therefore not receive any updates! Also in the GNOME settings, menu item "Info", it says that the system is not registered. When I click on "Register"-Button, there comes the message, that the system is already registered! My system is also correctly displayed as registered and active in my customer portal. I can also easily receive updates, that's not the problem. The very annoying problem is the constant pop-up notifications, that the system is NOT registered.

Several fresh clean-install did not help either, as did the manual removal and re-creation of the subscription management in the terminal with the following commands:

sudo subscription-manager remove --all
sudo subscription manager unregister
sudo subscription-manager clean

sudo subscription-manager register
sudo subscription-manager refresh
sudo subscription-manager attach --auto

What's going on there?