When you reflect a Ghast fireball and it hits under the Ghast in the middle, the explosion wipes out the Ghast loot and experience orbs that should have dropped. Please see the attached video that shows the bug happening on Minecraft Java 1.19.4 (Vanilla).

How to reproduce:
1. Summon a Ghast into a semi-caged area.
2. Get the Ghast's attention in survival to get him to shoot a fireball at you.
3. Reflect the Ghast's fireball towards the middle of the underside of the Ghast.