script is waiting an extra few seconds?

My script waits a few extra seconds and then disables? I am trying to make a some enemies stop following me by making their distance to me 0, I am using a value for this. here is my script:

Enemy Script

local larm = script.Parent:FindFirstChild("HumanoidRootPart")
local rarm = script.Parent:FindFirstChild("HumanoidRootPart")

function findNearestTorso(pos)
    local list = game.Workspace:children()
    local torso = nil
    local dist = script.Value.Value
    local temp = nil
    local human = nil
    local temp2 = nil
    for x = 1, #list do
        temp2 = list[x]
        if (temp2.className == "Model") and (temp2 ~= script.Parent) then
            temp = temp2:findFirstChild("HumanoidRootPart")
            human = temp2:findFirstChild("Humanoid")
            if (temp ~= nil) and (human ~= nil) and (human.Health > 0) then
                if (temp.Position - pos).magnitude < dist then
                    torso = temp
                    dist = (temp.Position - pos).magnitude
                end
            end
        end
    end
    return torso
end




while true do
    wait(1)
    local target = findNearestTorso(script.Parent.HumanoidRootPart.Position)
    if target ~= nil then
        script.Parent.Zombie:MoveTo(target.Position, target)
    end

end

Value Changing Script

local checkpoint = game.Workspace.Checkpoints.Checkpoint1

local connection = checkpoint.Touched:Connect(function(hit)
    if game.Players:GetPlayerFromCharacter(hit.Parent) then
        game.Workspace.Dark.Script.Value.Value = 35
        wait(15)
        script.Parent.CanCollide = false
        checkpoint.CanCollide = false
        script.Parent.BrickColor = BrickColor.new("Lime green")
        checkpoint.BrickColor = BrickColor.new("Lime green")
        game.Workspace.Checkpoints.Checkpoint2.BrickColor = BrickColor.new("Lime green")
        game.Workspace.Dark.Script.Value.Value = 0


        game.connection:Disconnect()
    end
end)