Apple seems to be locking and/or closing business developer accounts, even if they have an active app on the App Store. Unclear how widespread but I’ve had it happened to me and seen a few others in the last 48 hours.
Not sure what to do or if anything can be done - I’m sure having apps orphaned on the App Store is not what Apple wants either.
Regardless this is a heads up to others - make sure you have non-business accounts with admin access to your apps.
https://www.reddit.com/r/applehelp/s/DFzX0Rfyc2
https://www.reddit.com/r/iOSProgramming/s/FHmundoAKQ
tcook[at]apple[dot]com