Try a factory reset of the hub by pressing the recessed button with a pin for about 20 seconds until the lights flash.
Could be anything.
Up to you if you try a factory reset, it usually fixes most problems. All it does is put everything back to how it was the day you received it. Unless you have made any changes to the settings or passwords, you won't need to do anything other than switch smart setup off again. See here how to do that.