Shulkers Bullets Will Explode Inside of Shulker in the Overworld

I summoned some shulkers to fight, and the shulkers kept firing shulker bullets at me, but they just exploded inside of the shulker. The same thing happened when summoning them and adding them to my team. They tried to attack the pigman but the bullets just exploded inside of the shulkers. This bug works when the shulkers are hanging on walls or resting on the floor.