Grid placement not working correctly

Help and Feedback Scripting Support
,
#1

I’m making a simple grid system but for some reason when I try to put a block on the side -X it gets inside the other block as well when I try to put it on the bottom


This is my code:

local player = game.Players.LocalPlayer
local mouse = player:GetMouse()

local camera = game.Workspace.Camera

local Size = 2
local Grid = 2

mouse.Button1Down:Connect(function()
	local MouseOn = mouse.Target
	
	local Block = Instance.new("Part", game.Workspace)
	Block.Size = Vector3.new(Size, Size, Size)
	Block.Color = Color3.new(Random.new():NextNumber(0, 1), Random.new():NextNumber(0, 1), Random.new():NextNumber(0, 1))
	Block.Anchored = true	
	
	
	local PosX = math.floor(mouse.Hit.Position.X/Grid + 0.5) * Grid
	local PosY = math.floor(mouse.Hit.Position.Y/Grid + 0.5) * Grid
	local PosZ = math.floor(mouse.Hit.Position.Z/Grid + 0.5) * Grid
	
	Block.Position = Vector3.new(PosX, PosY, PosZ)
end)