When attempting to summon a piglin, if any spawn events are attempted to be used, the piglin's ai breaks. For example, if you summon a piglin by doing " /summon minecraft:piglin ~ ~ ~ minecraft:as_baby" the piglin is broken. In fact, it doesnt matter what you type as the spawn event. Any piglins summoned this way will have no weapons, will not become zombified in the overworld and will be peaceful to wither skeletons, even if they are given a weapon.