You are playing radio paradise to the Marantz it appears from the log. The Marantz reports Playback state stopped and position 0 when 27.5 seconds into the last track you hear playing.
Zone {Marantz SR7012} Playback state is PLAYING, We are playing radio paradise, load up the next track in the playlist. Position 272000, Duration 273000
Zone {Marantz SR7012} Playback state is PLAYING but GetPosition is returning 0. Estimated = 273547, Returned = 0
Zone {Marantz SR7012} Refreshing DLNA device state Position 273547, Duration 273000
Zone {Marantz SR7012} Playback state is PLAYING Position 1000, Duration 273000
Zone {Marantz SR7012} Playback state is PLAYING Position 7000, Duration 273000
Zone {Marantz SR7012} Playback state is PLAYING, We are playing radio paradise, load up the next track in the playlist. Position 7000, Duration 273000
Zone {Marantz SR7012} Playback state is PLAYING Position 14000, Duration 273000
Zone {Marantz SR7012} Playback state is PLAYING, We are playing radio paradise, load up the next track in the playlist. Position 14000, Duration 273000
Zone {Marantz SR7012} Playback state is PLAYING Position 20000, Duration 273000
Zone {Marantz SR7012} Playback state is PLAYING, We are playing radio paradise, load up the next track in the playlist. Position 20000, Duration 273000
Zone {Marantz SR7012} Playback state is PLAYING but GetPosition is returning 0. Estimated = 27500, Returned = 0
Zone {Marantz SR7012} Refreshing DLNA device state Position 27500, Duration 273000
Zone {Marantz SR7012} DLNA transport state CHANGED. Position 27500, Duration 273000 Previous 2, Now 0
Device stopped by another controller at: 28500 of 273000 MS
A few questions:
Do you have another DLNA controller running on your network?
What are the server options you are using for MC's DLNA controller that is associated with that Marantz? We need to know if the MC's converting the "stream".
In case the new Marantz can't do SetNextAVTransportURI properly you MAY have to disable that DLNA controller option in MC for that zone.