Missing privacy zone

I've set up a small square of privacy zone months ago once the fetaure was enabled for Ring Pro. Recently I wanted to edit that privacy zone; however although the black square is there, I cannot see this zone to edit in Privacy Zones page of the Ring App. The app promts me to add a new privacy zone, as if there does not exist any zone defined earlier at all. I can add new zones and edit or remove them. But this initial block square I've created is always there and I cannot do anything about it. Can you help me with this ?