Do other outputs work as expected and this behavior is just limited to the Peach Tree DAC? Is the behavior the same if you reboot your Core? Can you please share a screenshot of your Roon Settings -> Audio tab?
I have a PC attaching to a Peach tree AMP/DAC via USB. If the AMP is not set to the USB connection, the drivers will show as not enable- able. I would verify that the AMP is set for USB.
You have your computer attached by USB to the Peachtree. On the peachtree, you need to have pressed the USB button to select USB as the input or the computer (or Roon) will not recognize the AMP/DAC.
Hooray! I got it working. In Device Manager, the Peachtree device showed a faulty driver installation. I completely uninstalled, then reinstalled, and the ASIO driver is now working fine with Roon. Thanks for your attention.