Audio on songs cutting out partway through
I am replacing an iPod Nano that is no longer recognised by iTunes with my iPhone 8.
Having synced my music library to it, I am finding some of my non-Apple songs lose audio part-way through. They play fine in iTunes on the PC I used to sync with the iPhone. The song is still playing, but no sound is coming out. I am using the "Music" app the phone comes with.
I have tried turning the phone off and on, removing the songs and re-adding them, restoring the phone to a pre-music backup and a full erase-all-contents-and-treat-it-like-a-new-phone. The same thing happens with the same songs still.
Any suggestions, or do I try to get a second-hand iPod that works still?
The iPhone is on software version 14.4.