Squeezelite/Picoreplayer not playing a lot of ALAC files

Setup is LMS on a W10 PC and picoreplayer running on a 3b pi. Files are all ALAC. I have configured LMS & Picoreplayer to play these natively.

Problem is, some of my files only play the first few seconds or are completely silent. When I view the playback in the LMS console, it's playing the same few seconds over and over again, but there's no output.

Any ideas?

cheers