I wouldn't call a 2017 car old, depends on its condition.
I believe the handle is clipped into the black outer hatch panel. The black panel is secured with 7 plastic clips around its lower edge, but first you would need to remove the lower trim panel from inside the hatch and remove the items bolted to the rear panel behind the trim, which I think include the wiper motor. The mounting bolts are fixed to the upper part of the outer panel and also secure it to the main hatch panel.
There are several versions of the handle according to whether the car has standard central locking or keyless entry, and whether it has a rear parking camera. I would ask a Volvo dealer for the pert number for your car, which they can obtain from your VIN.
Suitable Volvo diagnostic software can also perform an actuation test on the switch signal and locking motor, and also read any related fault code stored in the CEM which would indicate the nature of the problem.