We have noticed that since a recent update the other week Call Queues are no longer working for some tenants. A client with Direct Routing had Call Queues setup and working however now it will not ring any of the member in the group, people calling in get into the queue, but the call cannot be answered.
Note. This is not with all tenants as call queues are still working for our own tenant.
Do they have Direct Routing numbers assigned to the Call Queues? That is not supported even if it looks like it is possible to fix with some SBC configuration.
If you use a Microsoft service number contact Microsoft Support, they will be able to see log files what is going wrong. You can create a new service request from Microsoft 365 admin center. You should be able to contact them even if you use a DR number for CQ.