Shipwrecks and buried treasure will not generate in stony shore biomes

Have you checked more than just this seed to see if this applies everywhere?

The bug here is that the buried treasure and shipwrecks won't spawn on mushroom beaches, even though they can spawn on the normal and frozen beaches. Using the same world type (large biomes) and seed (-281870521727245680) and teleporting to 69136 80 71568 will show a shipwreck that generated inside a regular beach (an intentional feature). These shipwrecks do not generate the same way in mushroom island shore biomes which is inconsistent and likely a bug.

This also applies to stone beaches, but I don't think it's a bug since it wouldn't make sense to find a chest embedded in stone (but it would be funny to find ships spawn at Y=120 a little more often than usual).

Can you add stone beach biomes as well? They also do not have shipwrecks and/or buried treasures. This is parity with bedrock edition.

Can confirm in 21w16a. Neither mushroom_field_shore.json nor stone_shore.json have shipwrecks listed, so it should be easy to fix.

Can confirm in 1.17