There is the bug where chest is enabled in hardcore world. Yes this is legit.

• Steps to Reproduce:

1. Create world

2. Do not turn on hardcore yet, turn on cheats first (it will shows "You can't earn achievement")

3. Turn on hardcore toggle, if it is still showing "You can't earn achievement", create world.

4. Try testing some command like /give

• Observed Results:

Cheats were allowed in hardcore world

• Expected Results:

Cheats should be disabled in hardcore