I've never used it before, but from everything I've read, zymes in general are not great for rdwc systems. I don't really know what cannazym is exactly, but just from checking out the website I saw:
"CANNAZYM prevents bacteria and harmful mold"
"CANNAZYM improves the soil environment."
Someone can chime in here if they have used it and been successful in rdwc, but perhaps it's having an adverse effect on the hydroguard? which is bacillus bacteria. I use gh rapid start with hydroguard, especially when they are young and growing roots. Personally I would drop the cannazym to see what happens. It definitely won't hurt your ladies. Hydroguard should be doing it's job just fine. If it's not working, something is affecting the hydroguard imo.