Topic: Why do I sometimes get WDM output on wrong channels?

I'm using a Babyface Pro FS over USB 3 on Windows 10 Pro. I'm using both stereo line and microphone ins, and I'm using both house monitor and headphone outs.
Additionally, I'm using the ADAT channels as virtual devices, so that I can set up routing separately for working in Cubase, listening to background music, doing general work on the computer, or being in Zoom. For example, in Zoom, I might want my music to stream back to participants, but it isn't part of the mix back into Cubase ASIO recording.
My music player is YouTube Music Desktop, and it's configured to send music to a channel that has lower gain than the regular computer audio.
So far, so good!

Unfortunately, every once in a while, the music from the YTMD program ends up showing up in a different channel in Total Mix FX than the channel it has opened -- this sometimes happens when switching to the next track.
To illustrate:

The patching setup:

With channel names:

Setting in YTMD:

When it switches wrong, the sound from YTMD ends up going into the "Computer" channel (AN 1/2) instead of the "Music" channel (AN 3/4)

Playing to the wrong channel did not happen with my previous audio interface (a Steinberg UR22.) However, as the Babyface has more channels, it's still possible that this is a problem with the YTMD application rather than with the RME drivers.
Whenever this happens, switching the configured device back and forth inside the YTMD application does send music back to the right device.

How do I debug this? Is there some event log I can turn on to see what device open requests the RME drivers get? This could be a problem in the YTMD application, or it could be a problem with the WDM driver confusing the output channels, and I have no god idea for how to proceed to try to fix this. Any suggestions appreciated!

(I wanted to also post screen shots of the control panel / versions, but the forum software won't let me. I have configured it to 48 kHz, 4 WDM devices. Driver version 1.212 and hardware revision 125.)


Re: Why do I sometimes get WDM output on wrong channels?

That's easy to debug. The moment you get the wrong routing enter Control Panel Sound Playback Device Properties and play the test tone. See where it comes out.

Matthias Carstens

Re: Why do I sometimes get WDM output on wrong channels?

Thanks for the answer!

That process doesn't quite work, because the music app is set to play to a non-default device, and the problem is that the music app switches to the default output. The control panel of course plays to the default output, as it should.

That being said, this feels more like an application problem than a driver problem, because navigating to different pages in the app does make it switch to the designated device. I'll see if the folks doing YTMD has something to say about it.