How do I check to see if a part is occupying an area? (LUAU Roblox)

I'm trying to code tetris, and I'm stumped because this code I have keeps on throwing errors. I have the function GetPartsAtPosition() checking if something is below the part that is going to move, to check if it can move or not. In Move(), I have it doing a loop through the pieces of the tetromino and using GetPartsAtPosition() on each of the pieces. It keeps on spouting random errors like Argument 1 missing or nil for the toucher variable definition line. With some pieces, they go down to the bottom and then the following pieces that spawn clump up at the top. With others, the clumping starts immediately. Here's a snippet of the code:

local function GetPartsAtPosition(Position :Vector3)local Touching = workspace:GetPartBoundsInBox(CFrame.new(Position), Vector3.one*0.1, OverlapParams.new())for i = 1, #Touching-1 do    local toucher = workspace.Pieces:WaitForChild(Touching[i],1)    if toucher then        if toucher.Position ~= Position then            table.remove(Touching, i)        end    else        table.remove(Touching, i)    endendreturn Touching or {} 

end

local function Move(piece:Instance)

wait(tickspeed*(level/3))local parts = piece:GetDescendants()local canMove = truefor i,v in pairs(parts) dolocal PartsAtPosition = GetPartsAtPosition(Vector3.new(v.Position.X+1,1,v.Position.Z))if #PartsAtPosition >= 1 then    print('Part detected!')    canMove = falseelse    print('No parts at that position')    endendfor i,v in pairs(parts) do    if v.Position.X >= -13 then        canMove = false    endendif canMove then    for i,v in pairs(parts) do        v.Position = v.Position + Vector3.new(1,0,0)    endendreturn canMove

end

Any help would be appreciated. Also, the piece moving down on the Tetris board would be an increase in the X value of the part.