How have you connected MC200 to G91? Are you using AC12/Reviver or a home made speakerlink dongle?

FWIW, my MC200 to DSP5000's via a SpeakerLink/DIN dongle provides seamless operation as one would expect. The latest firmware to DSP5000's changed the comms settings as per Carl's post and works a treat (albeit over zealous unmute operation on play). So the 4C change should do the trick and possibly points to some other config issue especially as you see no change after what is a critically important setting.

You press play on Sooloos, if it's like DSP speaker operation, it should, if required, turn system on, select source to AUX (SLS if label has been updated), unmute and play.

Meridian owner since 1992
Prime & PSU, Focal Elear headphones, Roon (ROCK 8Gi5 NUC), Explorer 1 & 2, F80. 200/203, various Sonos (via Roon).