Hi @calliopejane, thank you for reaching to the Sonos community and for letting us know about it. Your frustrations are completely understandable. I really appreciate all your effort in getting it resolved. Let me help you with this.

First, let me ask some questions to isolate the issue so we can create a path towards resolution.

1. When did it start happening?
2. Are you getting an error message when you play your Audible book in the Sonos app?
3. Have you tried using another mobile controller? Did you encounter the same?
4. Are you using an iOS or Android device? What is the model and software version?
5. Have you tried updating your Sonos system?

After checking the steps above and you're still having the same issue,
I recommend contacting our Sonos Customer Care support to remotely connecting to your device to further assist you with this and to provide the best option for you.

If you need help with any other information, please be sure to let us know.

The Sonos Community is always here to help.

1. I purchased the audiobook last week, but only started it on Saturday, which is when I discovered that this book is absent from my library if accessed via SONOS. 
2. There’s no error message, and Audible functions perfectly well for all the books that it will show. The ONLY problem is that my most recent book is simply not in my Audible library via SONOS. 
3. The book is missing regardless of whether I use the controller on my Android phone, my Windows 10 laptop, or my Windows 10 desktop. 
4. see answer 3
5. The system and all controllers are up to date.

The book is present in my Audible library, visible and playable in the Audible app, and shown in my Audible content online.  Only SONOS appears able to see only this one book.   I don’t know if the problem is going to persist beyond this one book because I haven’t bought another Audiobook after that one.

As I noted, a couple other people reported this problem last year, but no resolution is shown:
https://en.community.sonos.com/troubleshooting-228999/current-book-missing-from-audible-library-on-sonos-6830765

Hi @calliopejane, thank you for your response and for answering all my questions. I'm sorry to hear that you're still experiencing the same.

I really appreciate the time and effort you've spent doing all the troubleshooting steps, and it would be best for you to continue working with us over the phone to expedite the process. 

To further assist you on this, I recommend contacting our Sonos Customer Care. Our phone support has the tools to check what's going on in your system and remotely access your device and to provide the best option for you.

Let me know if you have any questions about this. We and the community are always here to help.

Me too.

This is a recurring problem and impacts multiple people.  Why direct people to CS when CS ought to respond here.  Just a thought.

Hi @Pcw-rider, thanks for reaching out to the Sonos community. We appreciate you for sharing your feedback with us. Allow me to share some information with you. We can provide troubleshooting steps, however, if none of the steps work, we refer to contact Sonos Customer Care support for more in-depth troubleshooting to isolate the issue. Our phone support has the tools to check what's going in the system by remotely accessing the device and to run some tests to help with a resolution. If you need help with any other information, please be sure to let us know.