I would like to put a cname in front of my VMC Vcetner, when I do so, get the error

[400] An error occurred while sending an authentication request to the vCenter Single Sign-On server - An error occurred when processing metadata during vCenter Single Sign-On setup: the service provider validation failed. Verify that the server URL is correct and is in FQDN format, or that the hostname is a trusted service provider alias.

There is a workaround for on-prem is in a kb, but obviously I cannot make these changes to a VMC environment.

https://kb.vmware.com/s/article/71387

Any thoughts how to get past this?

Thanks,

-GB