iphone 17 audiobook skipping & not playing

i listen to audiobooks purchased from the itunes store. the title i'm currently listening to frequently "skips" like a cd or lp might, with the words juddering and repeating. two sections don't play at all, but "minutes left" indicator zips to the end of the section & plays nothing.

my iphone 17 is a couple of months old. my ios is up to date. i've shut down and restarted my phone numerous times. i've deleted and reinstalled the Books app. i removed the download of the book and redownloaded it. none of these methods have helped.

any help much appreciated! thanks!