I couldn't find any fault
Odd. I even took the outputs to the 205 oscilloscope to see if I could see anything and nothing.
I noticed with VCA 3 depending on if in LIN/LOG the led will light up at different stages. In LIN, at 1 o'clock you see it's dimly lit. In LOG mode, it's 2 o'clock.
For the MIX VCA, it's kinda the same behavior depending on which combination of AC/DC and LIN/LOG are switched.
The module appears to work fine though, so I don't know.