A running server may still be waiting for media
Jellyfin documents a collection and playlist cleanup task and warns about unavailable media. On a server using a network mount, process startup and media readiness are different events. Check the configured trigger before treating a missing playlist item as an intentional removal.
Record the dependency explicitly
List when the operating system mounts the share and how the server's account verifies it. Review the task schedule in your installed version. If cleanup can run first, plan the timing around successful media availability rather than a guessed delay that merely works on an ordinary boot.
Preserve the relevant server data before changing the sequence. Do not unplug a live collection to demonstrate the risk. If a rehearsal is required, use an isolated library with disposable playlist entries and clearly separate writable data.
Check the result after a planned restart
Confirm that the expected filesystem is mounted, that a representative media file is readable and that the intended playlist entries remain. Record those three observations separately. A successful restart is useful evidence only when the dependencies required by the scheduled task were also present.
Questions answered
Sources & further reading
Official references for the subjects discussed. Service terms and device software can change.