The spawned object contains a root object sync, and 5 additional SyncPhysics object syncs: One is a Pickaxe pickup which is set to FollowTarget+LookatTarget a Player Tracker when not held. (the "Pickaxe")
The other 4 object syncs are just moved by triggers. We are not interested in those right now, though they suffer from the same bug.
Steps to reproduce:
1. Verify that each player should have the Pickaxe object next to their head. You should observe it syncs fairly well from most avatars.
2. Switch to AFK Avatar or any other generic.
3. Observe that the Pickaxe position will stop updating from other players' perspective.
4. If you hit c or z to crouch or prone, the Pickaxe (and other object syncs) should start updating again. [I found one Generic avatar that requires prone for objects to sync, but AFK avatar works with crouch or prone]
5. Switch back and forth with prone, or switch avatars to a humanoid. You can verify this behavior appears to be very consistent.