Hi, I just bought a "Simple Metal with Heated Bed" DIY kit and assembled it. When I tried to print, the z axis always do slight movements (up and down) but after finishing a layer it does not rise to next layer. It tries to print on the same layer, so z axis never moves up while printing. The printing goes on but since z axis does not move, it pushes away the layer it printed before and goes on. If you can help I can start my 3D printing journey.