Summary:
Some caves are duplicated in height (Y). Perhaps because of this, caves are also not generated in the same way as in Java.
An example can be found in any world, but here are a few seeds and coordinates:
Seed: -732078047
Coordinates: 4982.74 -10.43 3281.10 63 25
Coordinates: 5445.15 3.10 4118.23 -80 25
Coordinates: 5840.63 -17.03 4516.66 111 33
Coordinates: 6205.22 -26.17 4653.25 0 15
Seed: 8084476237860703793
Coordinates: 33.33 -20.82 210.15 40 14
Coordinates: 94.11 -24.39 256.03 -50 20
Coordinates: 167.99 -24.99 -43.84 -125 20
Coordinates: -99.01 -22.41 -79.86 -140 18
Step to reproduce:
Create a world with the seed above.
Switch to spectator mode.
Give yourself a night vision effect:
/effect @s night_vision 1000000 100 true
Teleport to the indicated coordinates. //wait for the world to load
Look at the caves that are targeted after teleportation (the direction is inscribed in the coordinates).
Observed results:
Caves are sometimes duplicated in height.
Expected results:
Caves are not duplicated.
Do you have more than one example? If not it may just be random coincedence.