If it is only the passenger side then it is likely the passenger side actuator not recirculation otherwise you would get cold feet as well (I think) I don't think it has a separation for left/right but it might.Having trouble with the recirculate door. It isn’t closed all the way and leaks. Heidi had cold feet for our trip. Maybe the actuator is messed up?
Try forward heat to confirm passenger side not working or not, use a thermometer to check both sides