In Java 1.20.1, seed 4722, at location X: -456 Z: 56, there is a shipwreck. According to the Wiki, any shipwreck that has two chests should have one of them be a map chest. From talking on the Shipwreck page, that map chest should be in the lower stern.

I checked this shipwreck, and it has two chests. But neither of them contains a map. Interestingly (and the only reason I mentioned the lower stern) is that the lower stern chest is completely full of loot, including two pieces of armor trim.

Is is possible that the map got overwritten by the armor trim, since that's brand new?

Anyhow, I'm writing this up because it MIGHT be a bug. But I can't be sure because I don't know how to access to code to find out.