After all the updates and changes around company structure and licensing it’s finally there the EOL of First-Gen control plane and customers should migrate to the Next-Gen control plane. This all sounds easy enough but at my customer who was still using the First-Gen control plane for licensing only the CSP logon that should present the Next-Gen control plane did not provide this. For this we opened up a support case and after some troubleshooting this resulted in a hard backend V1 option that needed to be switched to V2 and afterwards we would be able to logon to the First-Gen and Next-Gen control planes.
For reference:
V1 ends with /horizonadmin
V2 ends with /hcsadmin
Hope it helps