When I am uploading multiple tracks as a playlist a lot of things are going wrong. First of all, it's not creating any new playlist and the tracks got uploaded separate. So I have to create a new playlist. Besides the the artwork I uploaded is not attached to the separate tracks. So I have to upload it for each track manually.
This is going on for already more as half a year and being a label and uploading a lot of playlist it's irritating.
Hope this could be fixed soon :)