? in mp3 file name for playlists doesn't work

[jmpz]

One more experiment I tried:
I created a file in my playlist directory directly in the shell as empty?.m3u8, and populated it with a playlist I knew would throw an error, to see what the log showed for the file name encoding.

It comes back as:
Error: playlist _playlists/empty.m3u8: no matching file for ../Carta/Rehearsal Recordings/01 Track 01?.mp3

Another detail is that my file system on the Synology is BTRFS if that might make a difference.