I have been searching for a treasure chest on my world and cannot find the chest.

I have created a new world using the seed and coordinates and confirmed the location of the treasure chest in creative mode. However, my current survival world does not have a chest and the map is still active.

The chest is meant to be at 328, 57, -248. But as shown from the pictures attached, I have mined out the entire area and there is no chest. I also visited another shipwreck and obtained a second treasure map which was a duplicate of the first,

Seed: -1247870548
Treasure chest coordinates: 328, 57, -248