Ensure the latest firmware is installed, and as @killrob mentioned, you can try another cable. Another option is to run the gcode directly from the SD card. Put M17 in the header gcode, click the Save Gcode button, and rename the resulting file tmp.gcode. Place this file on the SD card in the xtool, replacing any that may be there. Then simply press the button on the front of the machine.
You can also send the file to the XTool wirelessly, I have a guide for this below;