Performed ac diagnostic on 30yr dedicated horizontal furnaces split systems. found that master bedroom is controlled by thermostat on far side of house. All of the bedrooms are controlled together. And living space is controlled by other thermostat. Master bedroom doesn’t get great airflow. Best airflow goes to master bedroom walk in closet. That’s because the unit and the bedroom are on other sides of the house. Tested both units working at this time. Due to age of the system don’t recommend any repairs. Recommend replacement. Found that bedrooms are all controlled together, and living space is other unit. If interested in replacement call back in and we can have our comfort advisor come back out and go over replacement options for 2 systems and duct work.