Steering wheel/USB disconnect

I am hoping you can help.
My wheel/usb disconnects regularly.

My setup is
simucube2 pro
sfx100 motion

without the motion on the wheel is okay
when the motion rig is turned on there is interference

I have tried the following

  • ferrite cores on everything

  • usb isolator - PC for the simucube

  • powered usb hub for wheel

  • ground wires on simucube

  • the motion rig is also grounded

I hope someone can help