Collisions not happening

I have a character with a bunch of colliders to act as hitboxes. I have an arrow/bullet that hits the character. Sometimes it works. The arrow works more consistently than the bullet (I'm guessing because of the speed of the object). I have collision on the bullet/arrow and the colliders on the character all set to continuous dynamic. I just shot two guys in the face with arrows, and both worked. Then the third it bounces right off his face, then the fourth and fifth same thing, the arrow bounces right off the head collider. The debug returns that it did in fact hit the first two, running the collision script, doing all the checks, and working as it should. However, for the third/fourth/fifth shots the debug shows that the arrow was colliding, but the tag was "Untagged". The first two are literally identical (it's a prefab), so for those getting hit in the face registers as Enemy, but for the others it's Untagged? Then the ones that weren't working, if I shot them in the chest, the arrow just flew through, ignoring the collider.

For the bullets, they don't register the majority of the time. They will definitely hit the colliders, because the bullet goes away, but it doesn't register at all. The debug doesn't even say a collision has taken place. Every now and then they work, but I have to shoot just to the side of the collider for some reason.

Clearly something is messing up in here, but I have no idea how to even begin. It seems incredibly simple, and I'm sure it's my fault, but it feels like Unity is deleting tags at runtime, at the very least, and at worst is ignoring colliders entirely.

Any help would be greatly appreciated. I'm very frustrated right now, lol.