Thanks for the suggestions Fiddler.

I simplified my configuration to only a CD player and Sooloos (ID40).

I connected a DVD player with analog outputs into the Analog Input to play a CD - the result no sound. I used both the front button on the 861 and the remote control to select the CD source. I also tried connecting to A1 and A3 on the analog input card and updating the config accordingly.

I confirmed that the DVD player was actually playing the CD by connecting into a stereo receiver that is connected to my TV in another room. It worked as expected.

Back to the Meridian system, the Sooloos worked perfectly.

When selecting the CD input, the speakers and the 861 all show CD Stereo and the volume, but no sound comes from the speakers.

This is a clue, but I am not sure what it means?

Anthem AVM70, 271, DSP7200x2, DSP7200.2HC, DSP5200x4, JL Audio F113,
Oppo UDP203, Panasonic UB9000, Kaleidescape Strato E, Apple TV 4K,
HDFury Vertex2, Epson LS10500, Stewart Filmscreen 110"