Hi Leo,
I also have an Virtuoso mount which I able to connect to stellarium via indi server (stellarmate) running on an Raspberry Pi4
the output showing disconnected state, when connected, the device list can show all available devices on indi server, such as mount, CCD, DSLR etc.
I also tried ASCOM driver, it requires Synscan Windows app running at background, it is a bit of weird setup. As I am using indi server for my other stuff such as CCD and DSLR control, my choice is via indi server connection.
Serial cable is another choice, I did not tried it