repeated buried treasure maps found in different locations

I have explored quite a few ocean temples and a few flooded ruins and found about six maps already. Five of them were buried treasure maps, and four of them were EXACTLY THE SAME. Two I found in a flooded ruin near the location of the treasure, so it could make some sense they are copies of eachother; but the other two were not from the same location! Why are the game algorythms generating so many copies of the same map?? You can see in the pictures that I have all maps lined up in different points of completion, they are not copies made by me. You can also see them all pointing to the same treasure (marked with the sign).