Using OH 2.4.0 M7:
Upon switching on a plug which has a Sonos speaker attached to it I get the following in my log
2018-12-11 08:23:43.733 [vent.ItemStateChangedEvent] - SteckdoseSonosSchlafzimmer_Switch changed from OFF to ON
2018-12-11 08:23:54.216 [vent.ItemStateChangedEvent] - SonosSchlafzimmer_Online changed from OFF to ON
2018-12-11 08:23:57.015 [me.event.ThingUpdatedEvent] - Thing ‘network:pingdevice:sonos_schlafzimmer_ping’ has been updated.
2018-12-11 08:24:01.553 [hingStatusInfoChangedEvent] - ‘sonos:One:RINCON_7828CA0092F401400’ changed from OFFLINE (COMMUNICATION_ERROR): The Sonos player RINCON_7828CA0092F401400 is not available in local network. to OFFLINE (COMMUNICATION_ERROR)
2018-12-11 08:24:06.357 [hingStatusInfoChangedEvent] - ‘sonos:One:RINCON_7828CA0092F401400’ changed from OFFLINE (COMMUNICATION_ERROR) to ONLINE
2018-12-11 08:24:06.386 [hingStatusInfoChangedEvent] - ‘sonos:One:RINCON_7828CA0092F401400’ changed from ONLINE to OFFLINE (COMMUNICATION_ERROR): The Sonos player RINCON is not available in local network. to OFFLINE (COMMUNICATION_ERROR)
As you can see, the speaker goes online and then immediately offline again. However, a ping (SonosSchlafzimmer_Online) returns success (=ON) and I can play music on it using the Sonos app. But given that in OH the speaker is marked as offline I cannot control it via OH. Note that the speaker is on the same subnet as the OH server.