The bug
Mobs can't control some rideable mobs.
All affected mobs:
Pig
Strider
Llama
Trader llama
Steps to reproduce
Use the following command:
/summon minecraft:pig ~ ~ ~ {Passengers:[{id:husk}]}
/summon minecraft:strider ~ ~ ~ {Passengers:[{id:husk}]}
/summon minecraft:llama ~ ~ ~ {Passengers:[{id:husk}],Tame:1b}
/summon minecraft:trader_llama ~ ~ ~ {Passengers:[{id:husk}],Tame:1b}
Confirmed.