Have you rebooted everything - including disconnecting from power?
I use my Meridian 251 (on my roof-terrace) with Roon almost every day (when the weather’s ok!) & the only problems I’ve had were down to internet / LAN connectivity and the 251 overheating (due to high ambient temperatures + direct sunlight).
Thank you for your answer.
It has been used well until recently, but only the “sooloos” connection is problematic, and no other source connection is problematic.