My spigot is in 1.8 and I use ViaRewind so that 1.7 players can join the server. I am trying to make a flag with Dopped Items so I use ArmorStands then I make the item ride the ArmorStand, for 1.8 players everything works fine but for 1.7 players, if the armorstand is spawned in the air (the gravity for the armorstand is disabled in code btw) the item just fall. In my opinion, the armorstand is replaced by a zombie in 1.7 but client-side, the zombie falls and doesn't stay in the air
Here's my code:

ArmorStand armorStand = (ArmorStand) player.getWorld().spawnEntity(player.getLocation().add(0, 2, 0), EntityType.ARMOR_STAND);
Item item = player.getWorld().dropItem(player.getLocation(), new ItemStack(Material.WOOL));
armorStand.setGravity(false);
armorStand.setVisible(false);
armorStand.setPassenger(item);

1.7 pov:

1.8 pov:

bump?

Check if the version is 1.7 and directly spawn a zombie instead of a armor stand and try to block zombie AI/movements