I just ripped “Kontor top of the clubs 54” to flac. I organised them as “Kontor top of the clubs vol. 54/Disc x/Tracknumber. trackartist - trackname”. I also edited the meta data with easytag so that the disc number is correct, album artist is “various artists” for all tracks and also the album name is the same for all of them.
Now, when I copy them to the music folder on my plex server, many tracks are missing. The first disc is complete, the second is missing number 10 to 20 except 18 and for the last one only 8, 11, 14 and 17 are shown.
I removed them from the server and copied them back with the whole “plex dance” procedure and the missing tracks are always the same. I also was not able to find any difference between those and the other files, all of them play perfectly in VLC