Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Dear Remo Ernst,
Thanks for visiting Microsoft Community. I am happy to help you.
I understand that your subscription was unavailable after you rejoined the Microsoft Developer Program.
Microsoft Developer Programs typically require accounts to maintain a certain level of activity or participation, and subscriptions may be suspended or deactivated if not active for a period of time.
Developer Program subscriptions have a complex relationship tied to the account, and there may be multiple account logins or authentication issues. Verify that you are using the same account when you rejoin; having multiple Microsoft accounts may result in inconsistent subscription information.
Your problem is more suitable to be posted at Microsoft Developer Community, where there are more specialized technical support staff with users to help you solve your problem.
Hopefully I can give you some information you can refer to.
Best regards
Miyeon.S - MSFT |Microsoft Community Support Specialist