Zone movements not working for automation

I have an automation

platform: zone
entity_id: person.bob
zone: zone.work
event: leave
id: leave_work

Now in that person’s history, I can see they are at work, and leave, today at 11am and 3pm.

However the automation was triggered only at 11am. Not 3pm.

How can this be, given the person location is clearly saved.