Norns ground noise [solved]

I’m looking for some help with a ground noise issue with a stock Norns and had no luck with this issue being addressed in other threads. I posted this issue in the Lorre Mill thread some months ago but have since gone through a process of deduction to arrive here.
Basically I am getting a very bad ground loop noise when I connect Norns to CV pal connected to other devices and then bring the audio (from Keyed Mosstone and or Double Knot) back into Norns. It doesn’t happen if the audio is plugged directly into an interface or mixer. This issue occurs if the Norns is battery powered, and occurs independently of other connected devices (grid, 16n ). As noted in the previous post, if I use 3.5mm TRS cables between cv pal and Lorre mill devices, and only partly insert them, I can eliminate the noise completely. Is there another option? The cables pop out at times during performances totally breaking the flow

Closing the loop here with my solution… a powered usb port and a ground loop isolator (I cant find a link to the isolator - the USB port is an old Belkin one that is 5V externally powered. I think the principle is the same as the ground loop adaptor which I would probably have tried next if this solution hadn’t worked.