World Seed: Coastal Village, -1813740965; Survival Mode, Hard Difficulty.
I found a Treasure Map in a Ruin's Chest (x=600 z=360). I went to the location on the map (x=472 z=-504). The treasure chest was not found. In place of the treasure chest, I found a sandstone block. I copied the seed and tried the Locate buriedtreasure command. The Locate confirmed the location was x=472 z=-504, see attachment.
I have tried several other treasure chest maps in this seed, but none of the maps produced a treasure chest. Here's another case: Ruins at x=-543 z=-202 with Treasure Map Red X; but Locate command shows x=-696 z=-248. No treasure chest at either location, refer to attachments.