You could have a problem wire in the wiring bundle to the passenger door that is intermittent.
When the weather cooperates I would remove the door panel and grab various groups of wires and move them around while watching the display screen for the HVAC and see if you can narrow it down.
The common area's for chafed or broken wires in the door harness is where the window goes up and down and might be in contact with some wires. And, also where the complete harness goes through the boot between the door and chassis (A Pillar area).
This harness is being flexed every time the door is opened and closed.
And lastly if you haven't found it by moving wiring around then I would disconnect the connectors to all things in the door that are related to the HVAC and inspect the electrical pins and sockets closely for any damage, bent pins, corroded pins and sockets, etc.