When trying to teleport an armorstand relatively to another armorstand it will not show up in the right position untill you save and quit the world and rejoin it. (or wait ingame for ~1 min)

To reproduce the problem:

summon two armorstands
/summon ArmorStand ~ ~ ~

{CustomName:"1",CustomNameVisible:1,NoGravity:1}

/summon ArmorStand ~ ~ ~

{CustomName:"2",CustomNameVisible:1,NoGravity:1}

Repeater command block:
tp @e[name=1] @e[name=2]

Chain command block:
/tp @e[name=1] ~ ~2 ~