Check the Service Health Dashbord for your tenant:
https://admin.microsoft.com/Adminportal/Home?source=applauncher#/servicehealth
There was an issue that has since been resolved that may be related:
Some users may have been unable to access the Exchange Online service via any connection method
EX469330, Last updated: November 21, 2022 9:06 AM
Start time: November 21, 2022 5:40 AM, End time: November 21, 2022 7:40 AM
Final status: We’ve determined that an unexpected issue with a section of infrastructure, responsible for regulating user traffic throughout the affected infrastructure, was causing impact. Our automated recovery systems returned the service to acceptable performance thresholds, and we’ve confirmed via service monitoring telemetry that impact is remediated.
Scope of impact: Impact was specific to some users who were served through the affected infrastructure in the Netherlands.
If that wasnt your issue: you can report it as well in that portal: