It appears that when you create a ULX vote, whether it be about the map change, or a votekick or voteban.
It only detects the numbers that are above your letters, as in, not the numpad.
Basically because the way garry's mod is setup, on the standard keyboard it has a row of numbers above the letters, all of these keys are considered "Number Slots" if you go in game, and type:
bind 1
It will return "1" = "slot1"
However, on a laptop the numpad keys take the spot of the numpad keys,
Such as, slot1 is bound to "+gm_special 1" on a laptop.
The thing is, on a lot of laptops, the top row of keys above the letters all the keys are bound special, so people with laptops have to rebind their keys to vote.