This is existing deployment which customer says configured under: xxxxxxxxx.prod.fire.glass.
There were no recent changes that would lead to this error, and there is also no production impact at the moment.
Web Isolation Cloud ver 1.16 Subscription
Working with the R&D team, it's been confirmed that CMP did not have the tenant-id present in the CMP system.
A renewal request was triggered from the backend, and the tenant ID added, to resolve the issue.