So my signal chain is bass > Gallows Sidechain in/out > Quad Cortex, with the main in/out of the Gallows in an effects loop.
The fault, when it appears, happens when a note is left ringing out for a few bars and, to my ears, the gate kicks in and lowers levels too soon, with the LED indicating that's what it's doing too (it changes colour when the gate is open and closed). As I say, it could be in my head as I have never managed to recreate it on purpose, and I do have the gate turned up high to make the gating action as hard and choppy as possible, which could be related too. I've gigged it for a couple of months without any problem, its only during bedroom noodling I've experienced it.