When i summon an armorstand and there is repeat commands like this:

execute @e[type=EntityHorse,tag=GbFB] ~ ~ ~ tp @e[type=ArmorStand,tag=GbFB,c=1] @e[type=EntityHorse,c=1]

tp @e[type=ArmorStand,tag=GbFB] ~ ~0.9 ~

The armorstand is teleported to the horse but the second command doesn't work. If I set the 2nd command to need redstone without powering it, the armorstand move downwards. And when power it I wait something like 1 minute, the command start to work. TheRedEngineer has already encountered this problem and I have the same in 1.9
https://youtu.be/uUB8WoV2v5A?t=1m20s