Wandering trader visual glitch

basically when the wandering trader becomes invisible the items he shows when you are holding an emerald start following the field of view of the player this does not work throwing a splash potion of invisibility on him only when he uses the potion on his own
"How to reproduce"
1) spawn a wandering trader
2) show him a emerald
3)spawn somethig that scares him
4)show him a emerald
(Visual glitch)