Explanation
https://docs.vmware.com/en/VMware-Cloud-on-AWS/services/com.vmware.vmc-aws-operations/GUID-ED8B8 By default, the management gateway firewall is set to deny all traffic between the internet and vCenter Server.
Verify that the appropriate firewall rules are in place.
The administrator can create an NSX firewall rule in the VMware Cloud data center that allows access to the vCenter from the on-premises data center. This would allow the VPN connection to connect to the vCenter, allowing the administrator to access and manage the VMware Cloud environment.