The crossbow_arrow is broken, due to the child model not actually appearing as it properly should, e.g. if you're making a 32x resourcepack you NEED to add the model from the 1.20.1 version of the crossbow_arrow.json, because for some reason, without doing so, the texture reverts to the vanilla textures. I'm not sure why this happens.

Below is the same resourcepack, one with the model included, one without, and the one without works as intended without an arrow loaded.

Edit: A mod is the culprit here, unsure of which one. Can't delete this, so.