Missing albums

[morgjeff]

Hi. I have a Spotify Premium subscription which has been working well for eighteen months but has now gone berserk. I have downloaded 50 or so albums to my iphone 5 and made them available offline. I used to be able to play and enjoy them all both inside and outside my home, but a few days ago, while I was out walking, I noticed that  most (though not all) of the albums had "disappeared" from my albums list  - by which I mean that the album titles still appeared on the list but the artists' pictures had been replaced by a note symbol and the tracks had all been "greyed out". Once I got back within wi-fi range they all magicallly reappeared. Every time I leave home now the same thing happens, although the albums are still available when I'm at home and on wi-fi. Can anyone shed any light on what's gone wrong and advise me on how to return to my previous state of listening bliss? Would be really grateful for any help...