started from version 1.19.4-pre2.

This phenomenon is not a major critical flaw, but it causes the entity below to appear as if it is moving like a robot. 

 

 
Spider jockeys and chicken jockeys are typical mobs affected by this, meaning that the entity below cannot turn its head toward the surrounding entities.

However, there are mobs that are not affected by this, such as piglins, villagers, ravager that carries all mobs with the raiders tag , and hoglins. 

Interestingly, during experimentation with these mobs, it has been observed that they can sometimes turn their heads 180 degrees to look behind them. If this is patched, it would seem more natural for the vehicle entity to only look at the surrounding entities and not at its rider.

How to reproduce:

1. Execute any of the following example commands:

   /summon chicken ~ ~ ~ {IsChickenJockey:1b,Passengers:[{id:"minecraft:zombie",IsBaby:1b}]}

   /summon minecraft:spider ~ ~ ~ {Passengers:[{id:"minecraft:skeleton",HandItems:[{id:"minecraft:bow",count:1},{}]}]}

   /summon vindicator ~ ~ ~ {Passengers:[{id:"minecraft:pillager",Patrolling:1b,patrol_target:[I;1,1,1]}]}

   /summon skeleton_horse ~ ~ ~ {SkeletonTrap:1b}

2. Approach closely to check if the entity below is looking at the surrounding entities (including the player).