Can't give a player speed depending on a value; player loading inconsistent?

Hi, I hope you are doing well.

I am trying to give a player speed depending on their "SpeedLevel," an int value found in a folder in the player. The problem is that the player doesn't gain any speed.

In this script, I try waiting 5 seconds to make sure the player is fully loaded but their walkspeed doesn't change. No error comes out.

This is in a regular script found under ServerScriptService.

game.Players.PlayerAdded:Connect(function(player)
    wait(5)
    local SpeedLevel = player.InfoFolder.SpeedLevel
    local WalkSpeed = player.Character.Humanoid.WalkSpeed

    WalkSpeed = WalkSpeed + (SpeedLevel.Value*3)
end)

Hopefully I have been clear, let me know if you need more info. Thanks!