Unable to access SCG GUI after stopping the SCG VM in Windows Hyper-V

We could access SCG GUI without problems, but the customer wanted to test and he stopped the SCG VM, then we are unable to access GUI. The page is loading and no error is shown.

We started a new installation from scratch and same issue.

The SCG is pingable via SSH and from the remote workstation we use.

Any idea what could be the cause and how to solve it?

Another question: customer stated that no way to "shutdown" the SCG VM, as the option to shutdown is grayed out. Is this as design for SCG VM? if yes, what if the customer wants put the ESXI server where this SCG VM is installed on for maintenance?