dirtgroove - sorry to hear about your pedal issues! Who cares how it tracks if the volume suddenly dropped 90% and won't come back!
I've heard of a common issue with these pedals, regarding solder joints inside the pedal cracking and needing to be reflowed, or something along those lines. Certainly a good place to start your search, and these symptoms might be what others have described in past threads. I'd also recommend contacting Akai, as Ive heard good things about their customer service, and iirc something like $50 to replace the bad solder. (assuming that is in fact the issue.)
Good luck with it!