True drive Accessory port interference?

I use my custom pedals and handbrake with sc2 pro accessory port, all axises map in true drive and works prefectly, except for a few buttons (button 9-10, sometimes 1and2), no devices connected with these buttons. However, they keep triggering themselves. Is there any interference that made this happened?

Look like an isolation problem, Electro Magnetic inerferences
Try to isolated your pedals PCB (if any) and use ferrite cables

Yeah, we only saw the similar behavior with grounding issues, or if the cable shield was connected to GND. That might also damage the Simucube or the pedals themselves.

Do not connect the cable shield to GND at any point.