Why Isn't the the NPC following the player when the player Is on top of a tower?

So I made a script that follows the player (But not only that but also has pathfinding! (Meaning It can go around walls when the player Is behind one and something similar about It)) but the problem Is where It can't spot the player when Its spawned on top of a tower (Ex: A office building, The classic roblox tower, A literal tree, etc)

script:

local NPC = script.Parent
local PathFinding = game:GetService("PathfindingService")
local player

game.Players.PlayerAdded:Connect(function(client)
    player = client
end)

repeat wait() until player ~= nil

local path

while wait() do
    path = PathFinding:CreatePath()

    path:ComputeAsync(NPC.Torso.Position, player.Character.PrimaryPart.Position)

    if path.Status == Enum.PathStatus.Success then
        local Positions = path:GetWaypoints()

        for i,v in pairs(Positions) do
            local Position = Instance.new("Part")
            Position.Parent = game.Workspace
            Position.Position = v.Position
            Position.Size = Vector3.new(3,3,3)
            Position.Anchored = true
            Position.CanCollide = false
            Position.Transparency = 1

            NPC.Humanoid:MoveTo(Position.Position)
            NPC.Humanoid.MoveToFinished:Wait(2)

            Position:Destroy()
        end
    end
end