Screen like covered with black square

Hi all,first post on here. I have a video doorbell 4 but for some reason when you view it i get a black screen, it's like someone has put a square piece of paper over the lens as you can very slightly see the edges . I have removed the battery and done a full factory reset and Wi-Fi is full and online. It just went like this, tried to look back at a delivery and Black, so tried live view and same.