I was able to update the Firmware for the BelCanto RefStream and I still have the issue of gaps between tracks. I spoke with BelCanto and they said it should support the SetNextAVTransportURI command. I also tried using the Id as a renderer rather than a server controlling it from the version of MC20 I have installed on my PC. Listening through headphones the Id also had gaps between tracks.
The Id is newly purchased: Id:20.0.100 MC:20.0.140-45. The PC version is older: 20.0.131 I can't recall if I have ever done an update. I originally purchased the PC version on 2/8/2015. I do not believe I had this issue when I originally installed MC20 on my PC and used it with the RefStream. I am certain I would have noticed it then. I have made changes to my home network since then, added the NAS drive, other network components...
All of my music is ripped from CD in windows lossless format. The DLNA settings are PCM-24 / 192. 24/96 also had the issue. All of my music is stored on a NAS drive although I have copied some files to the local drive and the issue did not go away.
Any other ideas about what the issue could be?
Let's just concentrate on MC as a server and the Id as a renderer to start with and leave the BelCanto out of the picture until you have the gapless working properly.
First, the DLNA server settings for Audio on the MC server should be:
Original format
(the rest doesn't matter).
On the Id, use a directly connected device to test, ie Analog, HDMI or a connected USB renderer.
Choose the front: or hw: device for the output device.
In the audio settings I ALWAYS use this:
Track Change: Gapless
Do not play silence: Unchecked
Use gapless for sequential: checked
Use gapless for manual: checked
seek: standard
stop: immediate
pause: immediate
BTW, I use those settings on the server too but they shouldn't affect your gapess test.
Try this and let us know the results.