When you place a map in an item frame, a green icon will appear. But then it disappears when you leave the game and come back.

When I place an map in an item frame, a green icon will appear. It occured to me that if I placed a map in an item frame in all my villages, then I would have a land mark on where they will be. It works and while I play, all the marks are there. But once I leave the game and come back, all the green marks are gone. They don't reappear until I come close to them. I have searched and it says they were resolved, but not for regular pc minecraft, just windows 10 and pocket edition.