Entity's not rendering unless the hitbox is on the screen

When you look at an entity and you don't look at the hitbox the entity renders normally

When you look at an entity and you don't look at the hitbox the entity doesn't render

Steps to Reproduce:
1. press f3 + B to see the entity's hitbox
2. You can either spawn a ghast and look at the end of it's hitbox
3. or you can use this command: /summon WitherBoss ~ ~5 ~ {Invul:5000,CustomName:Grumm}