Book and quills cannot be edited if they are renamed before being edited the first time. Steps to reproduce:
1 Craft/spawn in a book and quill
2 Rename it in a anvil WITHOUT opening it
3 Open it and try to type

If the book is edited before you rename it you will still be able to edit it after renaming it.

Edit:
After a little more experimentation I found if you click next page and then go back to the first page you can edit the first page. After typing some text you can click "Done" and then the book is fixed and can be edited freely.