2024-06-20, 09:05 PM
I'm going to say go ahead and submit a github issue. This feels like a race condition, as pcm suggested. ffmpeg hasn't fully stopped before Jellyfin attempts to delete the concat file, which is generated by ffmpeg while analyzing your music to determine the normalization value.
https://github.com/jellyfin/jellyfin/issues
https://github.com/jellyfin/jellyfin/issues