Armor is deleted when a villager converts to a witch

The bug

For some reason, villagers can wear armor when applied with a dispenser, although it’s invisible. When a villager that was given armor in this way dies, it drops the armor. When it turns into a zombie villager, the zombie villager keeps the armor (MC-261666). But when it turns into a witch, the armor is simply deleted. It is neither dropped nor kept on the witch.

How to reproduce

1. Put a diamond chestplate in a dispsenser

2. Spawn a villager in front

3. Activate the dispenser

4. /summon lightning_bolt

Expected behavior

The chestplate should probably immediately drop as an item, since witches cannot be given armor with dispensers. This is also what happens when villagers with armor convert into zombies.

Observed behavior

The chestplate is lost. It’s not dropped, and killing the witch doesn’t drop it either.