Sorry for trouble
But, thanks for your help
In Gizmo, it you tap on the Home bar, you will get a window with "Choose Where To Play" and "Choose a Server To Play From". My settings are "To play" -> MC_client: Audio. "Play from" -> MC_server. BubbleUPnP has the same kind of settings.
Here is what happens with my files:
Select through remote DLNA app (Gizmo, BubbleUPnp, ...)
MC_server: SACD iso, 2 ch -> MC_client Audio: plays at 2 ch, 48 kHz, 320 kbps
MC_server: SACD iso, multi ch -> MC_client Audio: hangs on "Opening..."
MC_server: FLAC, multi ch 96 kHz -> MC_client Audio: hangs on "Opening..."
MC_server: FLAC, 2 ch 44 kHz -> MC_client Audio: plays at 2 ch, 44 kHz, 320 kbps
Select through MC_server drag&drop on MC_client: Audio (no 3rd party remote apps)
MC_server: SACD iso, 2 ch -> MC_client: plays at 2 ch, 48 kHz, 320 kbps
MC_server: SACD iso, multi ch -> plays (badly) at 2 ch, 48 kHz, 320 kbps
MC_server: FLAC, multi ch 96 kHz -> MC_client: hangs on "Opening..."
MC_server: FLAC, 2 ch 44 kHz -> MC_client Audio: plays at 2 ch, 44 kHz, 320 kbps