Same issue here: 10th stomp switch, that is, bottom row, 4th from the left. It has false positive "touches" and "assigns" randomly and frequently.
I bought my Helix two months ago and the issue has been present on Firmware versions 2.11 and 2.12.
I'm going to see if I can isolate it. Maybe there's a particular connection, like USB or an XLR, maybe a bad ground from the wall outlet. I have the Helix plugged in to a surge protector also.
Honestly, I'm grabbing at straws to keep from having to be without it if it has to go back for service.
If I learn anything I'll update.