Water Pump Question

[Luna's Adventures]

2020 3121RL when we use the water pump if you run small amount of water out of any of the faucets or the toilet the pump kicks on but doesn't shut off. If you open a faucet again and let it run longer then shut the faucet off the system will re-pressurize and the pump will shut off. You can tell if the pump is going to keep running as it runs more quiet than if you run the pump longer. Any ideas on what is going on?