I too have had a hatch issue. The liftgate would unlock and lift using the switch in the front of the vehicle or the key bob. However, the handle switch would not open it. The handle would initiate closing, stop and reopen, but no open if the gate was closed. Replaced the switch in the handle - didn't fix it (OBTW: found a lot of dirt in the handle; it's doesn't have a gasket and collected a fine granular mix).

Replaced latching mechanism and it works again. Opened the old mechanism and, besides the gears and cam, saw a microswitch and some 'tronics in the housing. I suspect it was the sensing function in the latch that had failed.

I found OEM for a little more than $200 and generics for a little over a $100. Went OEM but it didn't come in a GM package. There was a sticker "made in Canada" but who knows - it works.

Hope this helps,
Jay