It appears this doesn’t work, because numeric state triggers only happen once each time the threshold is crossed.
So, if you are home, zone.home will be above 0 (= 1), and the trigger will fire. If you leave, the entity value is 0, which does not cross the threshold of 0 (even though it is no longer above 0), so it doesn’t reset. If you come home again, the entity value will go to 1, but it is still in range / hasn’t reset, so it won’t fire again.
https://community.home-assistant.io/t/home-zone-automation-not-triggering/