Errors of these kind generally refer to networking issues. How are your devices connected to your network? Roon and wifi generally don’t go together well. Ethernet connections are prefererend.
Please first verify that the issue occurs with an ethernet connection to the RoonServer machine per the post above.
Does this issue occur if you play to another endpoint, like the System Output of a Roon controller, or another networked Zone?
Do you have any DSP applied in MUSE when this occurs?
Please share a screenshot of both Signal Path and the Device Setup page for the Zone in your screenshot (the Hegel) from Settings → Audio.
We’ve requested diagnostic logging from the RoonServer machine in the meantime. Please turn on your RoonServer machine and connect from any controller so the upload to our servers can automatically proceed. Thank you!