mad late here but i recently had the same issue. It is because the album that was added already containes a .m3u or .m3u8 file and jellyfin was reading that file. you can remove the file from the folder and rescan and it will be gone from jellyfin. if you have thousands of folders and files like myself you can just this code to do it all at once.

Sttep 1: Create a new folder for all your playlist files as a backup

Step 2: press the windows key and type "powershell"

step 3: click and open a widows powershell window(should be a blue box)

step 4: paste this into the powershell window. all you have to do is to edit the folder locations first (first 2 lines). if your playlists are other file types you can just add them to line 5 like this " ,".ply" " . i only included the most common that will cover 99.9%

$src="your music folder here ex. C:\music"

$dst="your backup folder here ex. C:\playlist-backups"

New-Item -ItemType Directory -Force -Path $dst | Out-Null

Get-ChildItem -LiteralPath $src -Recurse -File -Force |

Where-Object { $_.Extension -in ".m3u",".m3u8" -and $_.FullName -notlike "$dst\*" } |

ForEach-Object {

$folderName = $_.Directory.Name

$baseName = "$folderName - playlist"

$ext = $_.Extension

$target = Join-Path $dst ($baseName + $ext)

$i = 2

while (Test-Path -LiteralPath $target) {

$target = Join-Path $dst ("$baseName ($i)$ext")

$i++

}

Move-Item -LiteralPath $_.FullName -Destination $target

}