Why do my tower dont detect distance from .magnitude?

Look, im making a tower defense game.

but when i try to make the magnitude part (to make the towers have a range and look at enemies)

It wont print the distance. take a look and please help me D:

local tower = workspace.Tower

local enabled = false

while true do
    wait()

    if enabled == false then
        enabled = true

        local attack = false

        for i, v in pairs(workspace.Enemies:GetChildren()) do
            local distance = (v.Position - script.Parent.Position).magnitude
            if distance < 15 and attack == false then
                print("ok")
            end
        end
    end
end

i mean, the enemy spawns but the tower dont get the distance, no errors or prints. and when its not duplicated (in the folder) it checks and print