I've discovered the territory with Vinicunca, and earned the star for doing so. I later claimed that territory. However an AI  show under their grievance on the Diplomacy/grievance screen that I 'stole Vinicunca' that they discovered first.  I assume this is a bug, either in the calculation for 'first' or in the UI?

Screenshots showing my earned star for discovering Vinivunca and their grievance attached.

In this match, I've been cultivating a good relationship with this AI so the grievance hasn't led to an incident (yet).
Humankind Lucy who was first 1.jpgHumankind Lucy who was first 2.jpg