Roon app doesn't see USB Dac attached to server

Plugged in USB DAC, FIIO BTR5, into Roon Server on QNAP TVS873. The device shows in the audio devices but neither my windows Roon app nor iphone app sees any audio output devices


HDA ATI HDMI at 0xfea64000 irq 73

1 [Generic ]: HDA-Intel - HD-Audio Generic
HD-Audio Generic at 0xfea60000 irq 74

2 [BTR5 ]: USB-Audio - FiiO BTR5
FiiO FiiO BTR5 at usb-0000:00:10.0-2, high speed

Make sure in device settings that it’s not a private zone.

Sorry if this is a silly question but did you enable it in Roon > Settings > Audio?

I’m running Roon on a QNAP NAS
The NAS interface shows the USB DAC as devices and I confirmed this by ssh terminal and running lsusb…which shows the USB DAC attached
I thought it might be the FIIO USB DAC so I tried a Schiit Modius and got the same results…
I was playing music through the Schiit Modius last night, everything seemed fine but this morning the Schiit USB device don’t show up as endpoint in either the windows Roon app or the IPhone app
And going to the Settings/Audio doesn’t show them as options

I thought I heard that some versions of QTS non longer support USB dacs @crieke might be able to advise as he maintains the Nas versions of Roon. I could be wrong though.