Is this the proper way to locate the position of a terrain block?

My goal is to make a script that will tell me if its parent brick is within a certain amount of studs from a specific spot in the terrain. Here is what I have so far:

local BRICK = script.Parent
local childPos = BRICK.Position
local t = game.Workspace.Terrain


local cellPos = t:WorldToCell(Vector3.new(childPos.x, (childPos.y - 1), childPos.z))
			local x = cellPos.x
			local y = cellPos.y
			local z = cellPos.z		
		

local rangeCheck = (childPos - cellPos).magnitude

print(childPos)
print(cellPos)
wait(5)
		if rangeCheck <= 10 then
			print("in range")
		else 
			print("not in range")
		end

The problem is, the position of the brick is correct, but the position of the terrain block is REALLLLLY far away. My question is, why does this not return the position of the terrain block closest to the brick? Thanks!