The bug

The bug is when you attack a mob or a mob sees you, they will follow you. But sometimes it will just stop following/attacking for like a second or 2.

(This happens to almost every hostile mobs, but in this clip I used enderman for demonstration)

However, like zombies/husks they seem to stop attacking the player sometimes after you hit it a few times, but oftenly do that when you behind a wall such as fence and cobblestone walls

This relates to my other bug that I reported 2 weeks back. See MC-147516