Need to make a mob unattackable but still drop items...

Hello all!
I have this simple mob that I am trying to make drop some items upon despawning. The reason I don't say upon death is because the way it works is that it spawns in, is unattackable, so no health bar/name upon being hit, and also can't be moved by being punched...
I figured out that if I set
Invincible: true

Then it solves this issue completely, however when the mob despawns via:
- suicide ~onInteract

It doesn't drop the items that are set to drop via the droptable...

Any help...

Need to make a mob unattackable but still drop items...