What is wrong with my Exp Bar Script?

I've made this script to display the player's Experience out of how much they need to level up. It resizes the Exp Bar, but when I change my Experience it doesn't resize the bar at all. What is wrong with it?

wait(2)

local xps = {0, 3, 6, 10, 15, 20, 25, 30, 40, 50,
    65, 80, 95, 110, 125, 140, 155, 180, 210,
    250, 300, 350, 400, 450, 500, 575, 650, 725,
    825, 1000};

function hudsize()
    local Player = game.Players.LocalPlayer
    repeat wait() until Player and Player.leaderstats
    local ExpBar = script.Parent.ExpBar
    local xp = Player.Exp.Value
    local level = Player.leaderstats.Level.Value


        local required = ((xps[level] * 100)/xp)
        wait(.1)
        local size = (required * 200)
        wait(.1)
        ExpBar.Size = UDim2.new(0,15,0,size)

        end

while wait(.5) do
    hudsize()
end

You should create a ValueChanged event to handle EXP value changes, so you don't have to check for them manually every half second, because that is inefficient. Next, your algorithm for calculating EXP is incorrect, instead, you should be dividing the EXP by the level. That'll give you the correct size and should correct the bug. Finally, either check my code or copy and paste it and test it, it should work.

wait(2)

local xps = {0, 3, 6, 10, 15, 20, 25, 30, 40, 50,
    65, 80, 95, 110, 125, 140, 155, 180, 210,
    250, 300, 350, 400, 450, 500, 575, 650, 725,
    825, 1000};

Player = game.Players.LocalPlayer

function hudsize()
	repeat wait() until Player and Player.leaderstats
	local ExpBar = script.Parent.ExpBar
	local xp = Player.Exp.Value
	local level = Player.leaderstats.Level.Value
	local required = math.ceil(xp / (xps[level] * 100))
	
	wait(.2)
	ExpBar.Size = UDim2.new(0, 15, 0,  required * 200)
end
	
Player.Exp.Changed:connect(function()
	hudsize()
end)