I had a similar issue for months, after reading a lot here I did the following:
- new wiring with double shielded wires
- grounded the shielding of the wires
- removed the power wire of DeWalt from drag chain
- updated Windows drivers
- externally powered USB hub between XController and PC
- switch energy safe options to full power (=do not switch anything off)
- switch USB energy safe mode to disabled (be careful here. It’s a separate option in the device manager for the USB root hub and not part of the general energy saving options)
- removed the USB bulkhead from the XController und connected directly to the board using a mini USB cable
- manually changed the baud rate of used COM port in Windows to 115xxx (was 9xxx)
One of the last three points did the trick for me. I would suggest testing the quick wins (4, 5, 7, 8, 9) first, since they are quickly done and cheap.