Apple Books - Audiobooks not Syncing correctly

I am stuck with some of my downloaded books not syncing correctly. A book that imported correctly to my library on Mac (7h of audio), only syncs to my iPhone as 4min audio. And I just can't find a way to make it work... All the sync is switched on in iCloud, but I sync them via cable anyway. Books downloaded as singular file seem to work, but books downloaded as chapters are not syncing correctly.

My suspicion is either:

  • Books that are downloaded as individual chapters only carry over the first chapter to the iPhone (why?!)
  • iPhone runs on iOS18 Beta, while the Mac is still on Sonoma 14.5, which may be causing the issue (?)
  • or something else entirely, that I am unaware of...

Anyway, any input, helpful articles or advice how to sort this out would be much appreciated!

Thanks.

Apple Books - Audiobooks not Syncing correctly
 
 
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