Blend door actuator locations

There is only a single blend door actuator that controls both sides in that system. As such it likely isn't the actuator if one side can switch temperatures but the other doesn't. Instead I would use a gauge set to see if the vehicle has a complete charge and if the compressor is operating properly. Either one could cause the core to only cool partially.
https://www.2carpros.com/articles/car-air-conditioner-not-working-or-is-weak
If the charge is OK but you still don't get cold air on one side I would use an inspection camera to see if there is something blocking airflow on the core.