I have the same problem. I tried to use several browsers (Microsoft's Internet Exploree. Google's Chrome and Oracle) with no results. I contacted Amazon Support, and I did everything it was suggested, but the "Add New Title" button will not work. Everything else works fine, except the Bookshelf. A friend if mine in Austin, TX has the same problem
which remained unsolved for over six months. It seems to be a program
glitch on the Amazon site. That's why I searched and publishe eight books on different platforms. I average seven sales per day. The main thing is not to get discouraged. Sooner or later Amazon will hire someoane who will be able to fix this problem.