usb ALSA failures

I have a new RME ADI-2 DAC connected to Volumio on Sparky. I leave Volumio powered on 24x7.

When first plugging USB cable into Sparky, ADI-2 DAC is recognized normally and music will play incl. 192/24 and DSD.

However, when powering off the ADI-2 and then powering back on, the USB connection is lost - no connection reported. When I play a song, Linux on the Sparky reports “failed to open ALSA device h/w 2,0 no such file or directory”. If I do a soft re-boot of volumio, the error persists. If I do a hard boot (power off on on), the ADI-2 is recognized again, and ADI-2 DAC State Overview shows USB connected - music plays!

USB off a Windows PC works normally

Any assistance to track down a solution to this issue would be greatly appreciated.

I use Volumio Primo–>RME ADI-2 DAC

Recently Volumio won’t recognize the RME DAC at all. The only playback options I get are analog and SPDIF. I’ve rebooted both sides to no avail.

And, yes, I can connect a PC to USB easily, no problem.