shulker and gamemode 3 (spectator) (bug/glitch)

shulker heads are following you if you are in gm3 (spectator)
i was seeing this when i did a kind off shulker vs shuler teamdeathmatch and i think its a glitch/bug
i made 2 screenshots
also if you put invisibility potions on them this happens (the time doesnt matter)(splash potions)