I also have the problem with the delay Amt, I bought my unit a few days and I've been through a few good. It seems that nothing works right.
In my case, every time you use the Delay Amt sound disappears, it is not any kind of noise, I have to move forward or back a preset and then return to where it was that sound again. It really is very annoying, I'm using analog lab2.
I also have problem in all my lower knobs when using VST inside ableton, to move the lower knob, simply nothing happens.
In No V2 business is worse, not in absolute terms or in relative mode can control the parameters.
Very annoying, I'm very sorry.