The achievements: Ahoy! (Find a shipwreck), Sail the seven seas (visit all ocean biomes) and Treasure Hunter (acquire a map from a cartohrapher villager, then enter the revealed structure) do not work, I should have all 3 of them and I haven't been given them.
Linked issues
duplicates 1
Comments 2
Duplicate of MCPE-33381 (Ahoy!), MCPE-22882 (Treasure hunter) and for Sail the seven seas, MCPE-34149 because you can only report one issue per report.
What version number are you using? (The affected version number given above can't be installed on Xbox One.)