Dan, just to be entirely clear: you are saving just the master config on the SD card for the master, and just the companion config on the SD card for the companion? (Sorry for suggesting you might be doing something else, if you're already familiar with the procedure...)
When the units start up, the master display should show the name of your configuration, and the slave should show "S1 config". Is that what you see?
When the units start up, the master display should show the name of your configuration, and the slave should show "S1 config". Is that what you see?
Roon (Mac Mini), Wilson Benesch Full Circle, Expert 1000 Pro CI, Kaiser Chiara
Warwickshire, UK