I have a minor issue with my ADI-2 Pro FS R BE - when switching from headphones (3/4) to main (1/2), I get a short spike of volume on AES digital output, then it ramps up as usual. This is not happening on the XLR outputs, only on AES digital. I suspect it might be a bug that can be fixed with software update.

Setup:
USB input to headphone (3/4) and AES digital (1/2)
Basic mode: DAC
Dig Out Source: Main Out
Mute v. TRS 1/2: On
Mute v. TRS 3/4: On