Kiting Treasure Guardians (health reset)

Hey all, noob question here as I learn the game. I’ve seen videos online of people kiting treasure guardians and not taking damage. Every time I try to kite, the treasure guardian runs back to the treasure and the health resets to full health.

Once you get outside of the circle of aggro, what do you do to keep their health from resetting?

Shoot one guardian and run. As soon as you get out of their aggro radius, they will attempt to go back to the treasure. Shoot again immediately and they will adopt a passive behavior for a while, allowing you to do a big chunk of damage before they react.

Do you need to walk back into the circle for them to not have their hp reset? Because I’ve seen them take on the passive behavior, but health still resets. See pictures: