Had a reply from the Google engineering team last night
"We understand how serious this problem is for you and the impact it had for users in your organization, according to the information from our engineering team the issue was fully resolved as of today Feb 10, 2021 2:20 PM CET. Our engineering team explained that the fix will gradually rolled out but at this point most of the affected accounts shouldn't experience the issue anymore.
Please confirm with the affected teachers if they're still experiencing the same issue. If they're still affected please allow up to 24 hours and try again, if after 24 hours you are still experiencing the same behavior, feel free to reply back and I'll be happy to re-open the investigation to push the fix for your account."
Seems to be working for me this morning.