I have some problems streaming from Roon to my Buchardt Audio A500 active speakers with the Audio Hub. Just an observation it looks like the same hardware that System Audio uses.
It supports Chromecast and is not Roon certified yet unfortunately. I must press pause and then play to begin streaming. Same thing (but not always) when the next in queue begins.
The problem comes back once in a while. Sometimes it works for hours and other days it’s every single time. I don’t know if it’s a Roon problem? Spotify Connect works every time