Tracks uploaded from browser don't play or show on iphone


I signed up for a monthly premium subscription, and uploaded 5 MP3s to VOX Music Cloud.
They were uploaded from my browers/your web site, because the link to the Windows app doesn’t seem to be working.
1 of the MP3s has uploaded fine and now appears in the VOX app on my iphone.
However the other 4 are reported us uploaded, but show in the browser as having zero length. And their track name is prepended with a “-”. These tracks don’t appear in VOX on my iphone at all.
Any suggestions?