Before anything else, note that this is not a problem on the player side. I invited a friend on my server to test this bug and he faced the same issue, and is therefore related to the world generation or the way the buried treasures are implemented in the game.

Description of the issue

• I obtain a buried treasure map in a new area of the world I'm playing on, either via a shipwreck or an ocean ruin, I find the location, and when starting digging, the chests are sometimes present, sometimes purely and simply missing, as if they had never been generated
• Out of 4 unique maps with unique locations throughout the world I'm playing, 2 chests were found and 2 were missing, despite both the locate command and buried treasure map leading to those locations

No need to say that this badly degrades the game experience, given how much we have to travel for them, how rare those chests are by default and how valuable their content is in this release.

Extra information

• Nobody else looted or destroyed the chests, I was in an unexplored area
• It was not in a mushroom island/shore biome, just regular beach biome
• I checked with spectator mode and there was no chest generated in the coordinates or even in the area nearby

Steps

• Map bring me to a buried treasure location, that I confirm using the locate command. Coordinates are 2137 ~ -1047
• I dig around, destroy the beach for 10 min with my shovel and pickaxe, no chest appear. I take a step back and take a screenshot (Buried_Treasure_Location)
• I decide to dig at the exact coordinates until bedrock, still no chest, so I take another screenshot showing F3 info as well (Buried_Treasure_Coordinates_Biome)
• I use spectator mode to try locate the chest, if it is anywhere, without any luck (see screenshot Buried_Treasure_Spectator)

If anybody has a solution or a valid explanation on why those chests are not being generated, I'll be happy to hear it! Otherwise, as I believe, there are some bugs in the buried treasure generation that will need to be fixed in an upcoming minecraft release