Just got a Mooer Tender Octaver - Noisy if before OD/Fuzz?

I just got a Mooer Tender Octaver and I've read that the Octave should be first before OD/Fuzz. But for some reason when I put it before my Way Huge Pork & Pickle, it emits a high pitched hum that only gets worse when the P&P is kicked on. Putting the Octaver after the P&P is quiet. Any reason why? It's not the patch cable. I tried different cables to make sure.

 

Ok, I found that if I put it on a different power supply, it's not noisy. But if it shares a power supply as my other 3 pedals, it's noisy. They're on a one-spot with a 5 way cord.