BasePart.Touched event not firing?

I need to make this script so that if a part touches the expanding red ball, it will 'liquify'. I put in a print command, but it only fires if it comes in contact with a player. Here's the code.

script.Parent.Touched:Connect(function(hit)
    print("Liquify touch")
    if not hit:IsDescendantOf(workspace.ReactorCore) then
        local humanoid = hit.Parent:FindFirstChild("Humanoid")

        if humanoid ~= nil then
            local flame = Instance.new("Fire", hit.Parent.HumanoidRootPart)
            flame.Color = script.Parent.Color
            wait(1)

            for _,v in pairs(hit.Parent:GetChildren()) do
                if v:IsA("BasePart") then
                    v.BrickColor = BrickColor.new("Really red")
                    v.Material = Enum.Material.Neon
                end
            end
            wait(1)

            local explosion = Instance.new("Explosion", workspace)
            explosion.Position = hit.Parent.HumanoidRootPart.Position
            humanoid.Health = 0

        elseif humanoid == nil then
            print("Melting")
            hit.BrickColor = script.Parent.BrickColor
            hit.Material = Enum.Material.Neon
            wait(2)
            hit.Anchored = false
        end
    end
end)

If anyone can tell me why it isn't working, I'd be very grateful.

• JB_SuperGamer

UPDATE: I have discovered that it will only melt unanchored parts. Does anyone know the cause of this?