@phunge – the emulated network card on your Hyper-V is not supported by ROCK.
ROCK is possible as a free offering to Roon users because it acts as support reduction mechanism for our company. We do this by supporting a few well tested configurations, and not extending support to more configurations.
This is not a configuration we support, so unfortunately, unless you can tweak it to work, there is not much we can offer you here. Additionally, if you do get it working, be aware that we may break it or any other “MOCK” setup in the future because we can not test all configurations besides the officially sanctioned devices.