The Audiobook filter doesn't show audiobooks that are in a book/folder together with an epub

[blinzler]

What went wrong?

Hi,
When you display all books and select Filter → Book Type → AUDIOBOOK, only standalone audiobooks are shown. However, if the m4b file is accompanied by a corresponding epub/pdf, these audiobooks are not included.

How can we reproduce it?

1. All books (left menu)
2. Filter for booktype AUDIOBOOK
3. You will see just clear audiobooks, but no audiobooks they are combined with ebook/pdf/and so on

What Build of Grimmory are you on?

Stable

Your setup

• Grimmory Version: 3.3.3
• Run on RaspberryPi 4 Docker
• Clients: Windows 11/Linux Min
• Browser: Firefox / Chrome

Screenshots or error messages (optional)

No response

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