Upstairs Lennox 2018 heat pump. System is cooling from equipment side but the problem is air balancing. I’m recommending 3 manual dampers and to direct more airflow into master bedroom zone. Would need 2-8’ and a 6’. Indoor air quality upgrades with existing filtration to clean every cubic ft of air upstairs would be a single UV germicidal light inside of air handler and ionizer connected to the blower motor.