You're stuck in the minor menu. Getting there is the first of three steps
needed to exit a book and get back to the library. Once you're in that
minor menu, you need to look around the top left. If you land on an option
like xray view, flick left and you should eventually reach where it says
"menu.
I forgot to mention that the menu appears but there's no option there to get
back to my bookshelf. I see viewing options, the location I am at in the book,
notebook, but no home or library buttons to be found.
This worked prior to the last update though I needed sighted help finding the
button a