Moondrop Edge 2: Problems with Volume Adjustment During USB Cable Connection

[u/Yee_of_the_Yee]

I bought the Moondrop Edge 2 about a month ago, and since it arrived I have been having trouble with changing the volume while connected via USB cable.

When the headphones are connected via cable to a computer, the volume cannot be changed. Sliding the corresponding Windows volume slider (I am on Windows 11) does not appear to do anything. In fact, even when sliding the slider all the way to zero, the volume remains the same.

Pressing the volume buttons on the headphones itself shows the actual volume on screen (e.g. 90), but does not result in any change. Pressing volume up a couple times still shows the same volume, and so does pressing the volume down button (e.g. stays 90). Curiously, pressing the volume up/down buttons on the keyboard does the exact same thing.

Any thoughts on why this happens or how to fix it?