I am running Virtualbox 7.0.4 r154605 and a Windows 11 Pro guest-vm running on a Windows 10 Pro host. No matter what port I assign using the VirtualBox Manager, when I start the vm, it will only respond to the default RDP port of 3389 . I have verified the port number change by using the vboxmanage showvminfo and it does show that the port number is assigned to the number I assigned in the VirtualBox Manager but the vm will only allow RDP request using port 3389.
Also I have configured the remote display authentication method to "External" using the VirtualBox Manager. However the vboxmanage showvminfo shows "VRDE property : Security/Method = <not set>". All VRDE properties besides "TCP/Ports" show as "<not set>".