Wither projectiles can break obsidian, this doesn't happen with the explosion it makes when you summon it

Edit:
When I say "The projectiles of the wither" I am referring to the heads of the wither that it launches to attack, to add more information, the most bluish heads are those that break obsidian. To reproduce the bug, you will need a wither, an entity close to it, and the wither to cast a bluish head ... and the entity to be close to obsidian.