Warden AI doesn't function properly when it rides on entities.
This results in the following situation:
Can't use close range attacks.
Can't use sonic boom attacks.
Won't play the roar animations.
Won't play the sniffing animations.
If the riding entity is a mob, warden can't control it.
Below is the command to reproduce:
/summon minecraft:boat ~ ~ ~ {Passengers:[{id:"warden"}]}
/summon minecraft:minecart ~ ~ ~ {Passengers:[{id:"warden"}]}
/summon minecraft:pig ~ ~ ~ {Passengers:[{id:"warden"}]}
Can confirm in 22w15a