Dear community,
I'm trying to establish a connection between an on prem SAP Cloud Connector instance and a SAP BTP trial subaccount (hosted on US region) and created with a universal ID account.
After creating the account and enabling the Cloud Foundry environment, I added an S-User to the subaccount with the assigned Cloud Connector Administrator role.
For information, there is no firewall / proxy restriction to communicate between on prem instance and SAP BTP account as this has been already configured and adjusted.
Below the error I have when trying to register my BTP subaccount in the Cloud Connector initial configuration setup page.

Could you please provide any insight on the root cause of this problem ?
Many thanks in advance.