Linn Majik DSM Found by Roon but music not starting

Since one week, Roon doesn’t play on my Linn Majik DSM any more.
Roon Core is installed on a Windows 10 laptop next to my Synology; The problem arises with all Roon instances (Remote, Core, MacOS, iOS, Android) and all sources (Qobuz, Tidal, own music on Synology). Re-start, de-activation and re activation of all devices (PC, Synlogy, Linn) did not help. I even downgraded the Linn software/firmware back latest non-beta, no luck.
The Linn works with Roon in Airplay mode (but not bit perfect) and with other sources like JRiver 25 in UPNP.
Roon works with other players, only the Linn is affected.
Tracks are shown but don’t start playing. The Linn is found as a possible audio player and can be removed and added.

Exactly the same with me…! ROCK Core, Linn Sneaky. Worked perfectly before ca. 3 weeks.