I also have a similar problem.. my tracks are missing.. as in not visible in my list, but the list still says it has 50 songs in it.. but you only see about 10 there when you open the list. Why cant I see these tracks?
The playlist was completely fine earlier today, but then I decided to buy Spotify Premium today, and after I bought it, the tracks were gone from view? This was also a new list I created today the same day I bought the premium.
Please help :)