The Bug:

Players and their riders sometimes momentarily face in the incorrect direction for other players when mounting horses, donkeys, or mules.

Steps to Reproduce:

1. Summon a horse equipped with a saddle by using the command provided below.

   /summon minecraft:horse ~ ~ ~ {Tame:1b,SaddleItem:{id:"minecraft:saddle",Count:1b}}

2. Get a player to mount the horse and have other players watch both the horse and the person mounting it closely.
3. Take note as to whether or not players and their riders sometimes momentarily face in the incorrect direction for other players when mounting horses, donkeys, or mules.

Observed Behavior:

Players and their riders sometimes momentarily face in the incorrect direction.

Expected Behavior:

Players and their riders would not sometimes momentarily face in the incorrect direction.