[1.16.5] Horus's Soaring does not always fly straight client side

[Kaleidio]

Your mod does not have a custom packet for the arrow's flight path, and since it inherits the vanilla one, it's expecting the exact same path of a vanilla arrow. So it only ends up syncing the entity's actual position every second or so, resulting in "two arrows" when only one is active on the server.

Whilst this would be the easier and more powerful solution, you could also check to make sure the gravity boolean is synced.