2x zoom briefly works with 3rd party lens attachment but quickly the screen goes black

I am using an iPhone 11 Pro with a 3rd party lens attachment. The lens has no problems and works well, but when I change the zoom to 2x, it briefly works and looks great, but then quickly the screen goes black. Too quickly for me to take a pic usually. Why is this happening? It seems like the iPhones lenses are shifting or changing on their own, is there a way I can stop that from happening?