This may depend on the unit. On mine, the sensor is mounted on the evaporator (freezer box) to sense the freezer temps.It may be too close to the freezer evaporator compartment and shutting off prematurely move it away from away from the evaporator so it will sense the box temperature.
Well we're talking about his not yours LOL and with no pictures no information that's the best guess from meThis may depend on the unit. On mine, the sensor is mounted on the evaporator (freezer box) to sense the freezer temps.