We're sorry you're not seeing the expected features in a book after upgrading your plan.
Typically, the issue here is that the book you're working on is a book where you are a co-author, rather than the book's "Primary Author".
The way this works is, the features available for the book are set according to the plan of the Primary Author of the book.
That way, the Primary Author can invite a co-author who does not have a Standard or Pro plan, and that co-author can still access the Standard or Pro plan features on that book.
The Primary Author can change who the Primary Author of the book is here:
...making sure to replace YOUR_BOOK with your book's unique web address.
Please note that who the Primary Author has some important ramifications; if you search our Terms of Service for "Primary Author" you can get the details:
We're sorry that's not clearer, we'll try to be better about communicating this.