Foreign Customs triggers for the player when an undiscovered Empire captured another undiscovered Empire's city. As far as I am aware, another Empire's city should not fulfill the requirements to unlock a civic for the player, much less an undiscovered city. Not long after this turn, I sailed over to the city of Parsa, but could not determine whether or not the city fulfills the requirements to unlock Foreign Customs in the first place. Does anyone know what the requirements are?

ForeignCustomsBug.ctr