Hi All,
Not sure if this is at all helpfull but I thought I had the Same issue but I am not 100% at the moment.
I am thinking the issue is someting to do with a particular block for me. Delay, Vintage Swell dips in and out of the Volumn.. The dips are over a long span I think It take 15seconds or so.. and it does feel like it this is what the Delay shouild be doing.. as soon as I use a different delay the issue goes away.
the amp block I am using with this is the Gramatc. Can give more info if required.