It looks like this device can be streamed to over the network via UPnP which is not a supported audio device in Roon. It looks like you can play to the device via USB as well — Have you tried playing to the device from Roon in this way?
Thanks for the quick answer. In fact its connected via UPnP. I will try your suggestion.
But even if it works it would be even better, if Roon could be updated to connect via UPnP. Is there any hope to it?