Why do some green flags have 3 stars under them?

They are so called „First to Capture“ or „FTC“ that means an item, which was deployed and not captured for 90 days.

This item is marked with 3 stars since it was capped for the first time..

This first capture is possible (as with JumperFlags) within 60 seconds for any number of players and brings tripple points.

Sample of FTC’s