Mobs with high value of generic.step_height are unable to step up fence or wall

The Bug

When a mob with high generic.step_height value, it can step up a tall pillar, but can not step up the fence or wall

Steps to Reproduce:

1. Build a 2 blocks high platform.
2. Summon a vindicator that can step up 2 blocks high outside of the platform.

   /execute summon minecraft:vindicator run attribute @s minecraft:generic.step_height base set 2

3. Go to the platform and change your gamemode to survival or adventure.
   → The vindicator step up the platform and chop you.
4. Change your gamemode to creative and enclose the platform with fence or wall, now you can destroy the platform and leave only the fence or wall
   -> Vindicator can see you and want to attack you, but it can't step up the fence or wall.