I have recently built a Wither Boss containment room made from obsidian. Have spawned in the Wither a few times and killed him with iron golems. So far not a single obsidian block has been broken by the Wither. Is this a change in the game or a glitch?
There are a few possible causes:
- The black wither skulls can only destroy blocks with a blast resistance of 20 or less (source). Obsidian has a blast resistance of 6000. Blue skulls can destroy any block except for bedrock and command blocks. It's possible that no blue skulls ever hit the obsidian.
- As mentioned here, if the gamerule
mobGriefingis set to
false, mobs won't be able to pick up or destroy items (source). Try running the command
/gamerule mobGriefing trueand see if that does it.
- If neither of the above are true, it could be a glitch or bug. If it continues occurring, you can report it here.