As Hacking Rulez said, you need to make sure that if you are not all level 20 yet, you need to set your speed using the menu at the top of your screen. This configures the speed of all the characters in your party to match that of the slowest party member. Then once you reach level 20 with all of your multi boxers, you can then set the speed and only set the speed again when you equip and dequip items that change the speed of a party member. If it is anything else try to contact Kronk on skype and see if you can get support there.