This issue is related to the cable. Due to the recessed connector on the Tablet, sometimes the cable does not reach all the way in.
On some cables, the outside diameters are thicker in dimension thus giving a false feeling of being connected to the unit when it is not making full contact.
Please use the cable USB to USBc in the box to connect your controller to the tablet. You can also learn more about the cables to use on this thread: