The Bug:

A desync occurs when leads are attached to entities that are just barely out of reach.

Client-side, it appears like a lead is attached to the said entity and will not break no matter how far away you go.

Steps to Reproduce:

1. Enter creative mode and obtain a lead.
2. Summon a boat and attach a lead to it.
3. Fly upwards in the air and as the boat travels downward, quickly detach and reattach the lead to it.

Observed Behavior:

A desync occurs resulting in the lead attaching to the entity client-side, but not server-side.

Expected Behavior:

No desync occurs.