More information may be available via the Microsoft admin portal, though users can't log in to see this because of the same prolem.
Quoting the status.office.com report:
Title: Error when attempting to access Microsoft 365 services
User Impact: Users may receive an error when attempting to access Microsoft 365 services.
More info: Users may the following error message: "AADSTS90033: A transient error has occurred. Please try again."
Current status: We're investigating a potential issue and checking for impact to your organization. We'll provide an update within 30 minutes. Scope of impact: Users hosted in the Australia or New Zealand region may be affected by this event.