In survial mode,when shulker gets hit,there is a aggression spread in a distance.
Normally,shulkers only hit player when they can see players in 16 blocks wihout being blocked.
With the aggression spread,the shulker who got aggression spread won't lose target in anyway((!)include change into creative or spector) but leave the coordinate of the spread's starting point,or the aggressed shulker got hit by shulker bullet and triggered teleport.

Video:https://www.bilibili.com/video/BV1R5PUeaE9F

save uploaded

To reproduce the bug:
1.make a wall that's big enough to block shulkers' sight
2.put a shulker in each side,make sure they are all within 16 blocks of you
3.stand in one side,make sure you only get seen by one shulker(A)

4.change into survival mode,hit the shulker in your side
5.the shulker in the other side(B) will start to attack you, bug gets triggered
6.change into other mode,shulker(B) still attacks you