I am having the same issue. I am one week into the Roon experience (really liking it so far) and have two Sonos devices connected via WiFi (Play 1 and Playbar). The Playbar played flawlessly last night and tonight it just isn’t showing up in the audio devices in Roon. It does show up and work properly in both the Sonos app and the Tidal iPhone app. The Play 1 has remained on the device listing.
Running the 1.4 controller on a MacBook Pro with thunderbolt RAID array. WiFi is a mesh network with a unit in the same room as the Playbar. Critical listening is by way of an iFi nano DSD DAC/headphone amp connected via USB to the MacBook, but the convenience of the Sonos speakers is a great complement to that for more passive listening in other rooms.