Could be a fuse but not likely unless you didn't notice the other functions not working F86 in the CEM but this also feeds the rear reading lights, power seat switches and the fuel tank level indicator (fuel gauge). So unless those are also not working then the culprit is likely the rear hatch release motor as the power runs through that.
May want to check for power and ground at the hatch release if the fuse is good. Pin 4 is power and Pin 2 is ground. I'd also check for power in the light socket with the lift gate open to chassis ground to isolate the grounding point as a possible source. Ground point is the front left seat riser next to the B-piller if it goes back that far for fault tracing (may want to give that visual inspection for corrosion and tightness or any damaged wires) although the ground point failure is least likely due to everything else that grounds there as well.