[SOLVED] Why is not my model being placed when I click when my mouse is hovering the cells?

Why is not my model being placed when I click?

So.. I am developing / scripting a placement system for models, and what I want it to do, is that the model can only be placed if the mouse / preview of the model is on the "Cells" I created.

If you do not understand what I am trying to accomplish, then think of the placement system in Miner's Haven, I want the model only to get placed whenever the preview / mouse is over the "cells".

I have tried the following(See code below). I know for certain that I am indeed doing something wrong, but that is why I seek help here.

Please note: I am not asking for anyone to create a script for me, all I really want to know is what I am doing wrong, and what I could do to fix what I am doing wrong.

Any help is greatly appreciated!

Coding for my placement system:

local rs = game:WaitForChild("ReplicatedStorage")
local model = rs:WaitForChild("ModelToPlace")

local cells = game.Workspace.Cells:GetChildren() --The "Cells" the model CAN / SHOULD be placed on, the cells has a "Studs" surface
												 -- There is a model called "Cells" with all the cells in them
local player = game.Players.LocalPlayer
local mouse = player:GetMouse()

local runService = game:GetService("RunService")

local cloneModel = model:Clone()
cloneModel.Parent = game.Workspace
local modelCFrame = cloneModel:GetModelCFrame()
mouse.TargetFilter = cloneModel
function roundAToB(a,b)
	return(math.floor((a/b)+0.5)*b)
end
runService.RenderStepped:connect(function()
	local hit = mouse.Hit.p
	--CloneModel:SetPrimaryPartCFrame(CFrame.new(hit)*CFrame.new(0,modelCFrame.Y/2,0))
	cloneModel:SetPrimaryPartCFrame(CFrame.new(roundAToB(hit.X,1),1.5,roundAToB(hit.Z,1)) * CFrame.Angles(0,0,math.rad(0)))
end)
mouse.Button1Down:connect(function()
	if mouse.TargetSurface == cells.TopSurface then --This should in my head check if the mouse / preview is hovering the cells, but it does not work. Why?
		local new = cloneModel:Clone()				--And nothing gets placed anywhere because of what it says  in the above comment^
		new.Parent = cloneModel.Parent
	end
end)

mouse.TargetSurface returns the side of the part, such as top or bottom. cells.TopSurface returns the appearance of that side. they're not comparable.

Next time try printing this stuff out yourself.

To compare surfaces, do

local targetSurface
if mouse.Target then
    targetSurface = mouse.Target.TopSurface
end
if targetSurface == cells.TopSurface then