Morph Parts Falling Through Floor

[EdugamesBR146]

You can write your topic however you want, but you need to answer these questions:

1. What do you want to achieve? Keep it simple and clear!
   Basically I made a simple morph system for my Jujutsu Kaisen based game, and in some of the morphs, the parts will fall through the ground. (Only happens with meshes)

2. What is the issue? Include screenshots / videos if possible!
   The morph parts fall through the floor dispiting being both massless, unanchored and welded to the main parts
   

3. What solutions have you tried so far? Did you look for solutions on the Developer Hub?
   I did some tries, but none of them did work at all.

After that, you should include more details if you have any. Try to make your topic as descriptive as possible, so that it’s easier for people to help you!

local morphClone = GOJO:Clone()

for _, item in pairs(morphClone:GetDescendants()) do
    if item:IsA("Accessory") or item:IsA("Hat") then
        -- My Code Logic For Accessory
    elseif item:IsA("Decal") then
        -- My Code Logic for Decal
    elseif item:IsA("Part") and item.Parent.Name == "Head" then
        -- My Code Logic for Part
    elseif item:IsA("Model") then
        -- My Code Logic For Models
    elseif item:IsA("MeshPart") then
        if OldChar:FindFirstChild(item.Parent.Name) then
            local WC = item:FindFirstChildOfClass("WeldConstraint")
            
            local new = item:Clone()
            new.CFrame = CFrame.new(
                OldChar:WaitForChild(item.Parent.Name).CFrame.X,
                OldChar:WaitForChild(item.Parent.Name).CFrame.Y + (item.CFrame.Y - morphClone:WaitForChild(item.Parent.Name).CFrame.Y),
                OldChar:WaitForChild(item.Parent.Name).CFrame.Z
            )
            new.Parent = OldChar:WaitForChild(item.Parent.Name)
            
            if WC then
                WC:Destroy()
            end
            
            local NewWC = Instance.new("WeldConstraint", item)
            NewWC.Part0 = OldChar:WaitForChild(item.Parent.Name)
            NewWC.Part1 = item
            
            print("Part0: " .. NewWC.Part0.Parent.Name, "Part1: " .. NewWC.Part1.Name)
        end
    
    elseif item:IsA("Shirt") then
        -- Code Logic For Shirt
    elseif item:IsA("Pants") then
        -- Code Logic for Pants
    end
end

Please do not ask people to write entire scripts or design entire systems for you. If you can’t answer the three questions above, you should probably pick a different category.

[Dacarknowsalot (Car)]

Is CanCollide enabled? It might be because its not colliding it will just fall through the floor.

[EdugamesBR146]

Thing is, with models and almost the exact same code and the exact same welding it does work perfectly, so I just grouped everything I needed as a model and now It works