hello sir bugsalot I mean there is a quest and to solve it you have to discover treasures on the map. Like the round island. Hope you understand my english.
You must uncover all spaces of an island for it to count. If the name of the island does not appear above it then you haven't fully discovered it. The quests have a percentage indicator, is it at 100%? Did you tap the completed icon on the quest if it was completed? If none of this helped, you should contact support@rovio.com
You'd have to ask Midoki. My thought has always been that after you discovered the perimeter that you send in a scouting party