In the shipwreck chests that usually spawn a treasure map, treasure maps are not spawning, but loot that usually spawns in underground treasure chests are spawning instead.

I found this twice so far.
First cheat spawned a heart of the sea instead of a treasure map (didn’t record coords)
Second chest spawned a diamond instead of the treasure map (chest at -709 51 1582. Emptied it by accident)

If I find another one, I’ll link a screenshot

 

Oh really? May I ask why, or is it something that you cannot say?