The bug

I replaced the arrow texture with a partially transparent texture. In Minecraft, the partially transparent parts of the texture are replaced with completely opaque pixels, sometimes the arrow is transparent and works as expected (but this only happens on multiplayer - I've tested it on spigot)

How to reproduce

1. Put on attached resource pack
2. Go in to survival, shoot yourself with an arrow
3. Hold the bow, and arrows are opaque
4. Do not hold any item, and arrows are transparent
5. Arrows on the ground and in the air are not transparent either