https://www.bleepingcomputer.com/news/microsoft/microsoft-licensing-issue-blocks-microsoft-365-family-for-some-users/

Microsoft is investigating a potential licensing issue blocking access to Microsoft 365 services for some customers with Family subscriptions.

After a massive wave of user reports on social media and the company's community website, Microsoft confirmed that some customers could no longer access Microsoft 365 using subscriptions that have yet to expire.