files with ë or é etc do not make it into playlist

[MiniMe]

Yep the filenames were local Mac generated, local Mac appended the right volume address, and then playlist was copied onto NAS. This would break the playlist as you indicated, in case of non ascii.
If I (test) create the .m3u8 while working on NAS folder / server side and not doing anything local Mac the playlist works fully but at the expense of time and flexibility.

[simoncn]

You can use the iconv command on the Mac to convert the NFD playlist into an NFC playlist. For example, this command:

iconv -f UTF-8-MAC -t UTF-8 example.m3u8 > example2.m3u8

will create a file example2.m3u8 that has all NFD characters converted to NFC.

[MiniMe]

that's super helpful

I used grep -p -n "[^ -~]" example.m3u8 that helped me list out 99% of list names with strange characters.

Since db moves between systems here and there I decided to replace the strange characters by ascii a-z to resolve all compatibility / language issues.
Problem solved.

Thanks for helping with the clues, I appreciate!