Thanks for the wiring diagram @knfenimore. I agree, the multiplexer sure looks to be the suspect here. I am a little baffled by one thing though. The OP stated the rear hatch actuator stopped working along with the driver side door but the rear hatch is tied to power along with the rear doors, not the driver's door. I can't explain how that could happen unless the hatch really went out with the rear doors.
Before doing any parts replacement I would make sure that power and ground connections to the circuit are good as that very well could be the real cause of issue here. If the multiplexer doesn't get enough current drive for the motors due to a power problem they won't work and the rear doors will have the greatest load on the circuit since there are four motors in parallel with each other. The driver's door has its own own circuit leg. The resistance to the front passenger side door may have a little less resistance in it compared to the rear doors and may explain why it worked a little longer, until more added resistance in the power line killed it also.