audiobook chapter not working properly

i’m listening to an audiobook on books app on iphone 12. most of the chapters (tracks) last 5 minutes 45 seconds. but 1 chapter is listed as 10 seconds long & contains no audio. the player progress dot sort of skips through the play with no sound & then goes to next chapter.

i’ve listened to this book once a few years ago & i don’t recall this problem before. i can’t find anything in book settings or within the player settings.