USB Sound Blaster Omni crashing AirPlay?

Hi, I have a quick question. I’m using the latest MusicBox (RC7) on RPi 3B+ and with Sound Blaster Omni connected to the USB port.

MusicBox initially shows on the AirPlay devices list, but after trying to play anything, Airplay seems to be crashing and disappears from the list until I reboot MB.

It’s working just fine when I select the Analog output. Has anyone come across this issue?

Many thanks in advance for any clues.