I have found a verified instance of this happening within survival gameplay.
Seed: -977370421092973490
Coordinates: -632 65 -3640
Loot Chest: Buried treasure
Expectation: Must include 1 “Heart of the Sea”
Result: Does not include any “Heart of the Sea”
Apparently the loot is different between versions so this repeatable instance only appears as such on iOS as far as I’m currently aware.
This still affects 1.21.131