the DAC USB port USB 1-9 does not like the requested samplerate cannot set freq 44100
in the OP it was cannot set freq 48000
If another audio stream was using the DAC, the device may be using a different sample rate to discord. But there is no information about any other active audio streams
Have you followed online suggestions for alleged ‘audiophile’ settings and changed PulseAudio to avoid-resampling?
Or do you have Discord configured to try to connect to the DAC instead of ‘default’ playback (via PulseAudio)?
Audio interfaces and DACs can be temperamental devices that do not work well with external USB hubs, or sharing an internal USB hub
The Logitech Unifying Receiver appears to be using USB 1.1 (UHCI or OHCI) - 12 Mb/s
wheras the C-Media Schiit Modi 3 is using USB 2.0 (EHCI) - 480 Mb/s
(you can check this in lsusb)
The two devices are sharing data on a shared connection at different rates
And having a radio transmitter/receiver close to the DAC connection may not help
I can only really connect my Logitech receiver to the top USB plug of my case, as if I plug it into the back I think its too far away because then my mouse will occasionally stutter.
If the wireless device has already been unreliable you should replace it to troubleshoot the DAC
I do not know many users who tolerate using a wireless mouse, but they usually stick the receiver to the underside of the desk directly below the mouse
I suggest you get a USB extension cable for the wireless device and place it close to the mouse and away from the DAC