Stellar Gain DAC not recognized by iMac all of a sudden

My system: S700 monos triggered by Stellar Gain DAC/Preamp, all plugged into a Stellar Power Plant 3.

When I shut my system down using the preamp remote (which I’ve done hundreds of times, leaving the PP3 on), then turn the system on using the same remote, the DAC is not recognized.

If I shut the PP off with ITS remote, then turn back on with that remote, all is well with the world.

I must admit that I’ve been on vacation for a month, so I’m still getting back to normal here. But I don’t remember this system behavior.

Before I left for vacay, I turned all above boxes’ master switches off and unplugged everything. When I returned, I re-plugged and switched on.

Did I do something above in the wrong order to cause this?

Thanks all.