Offline albums are empty (sometimes)

[otsenresiul]

[iPhone 4S - iOS 9.3.2 - 1.1 GB available - Spotify app version: 5.7.0]

Hi all. I used to have an iPhone 4, save offline albums and it worked perfectly without 3G or wifi.

I just got an iPhone 4S and things are a bit weird now...

I saved a few albums offline while being on a wifi connection. I left the connection and the albums were there, but when I accesed to them it said:

You haven't saved anything from (name of the album). Save this album to keep it in your music.

Weird thing is the album was already saved in My Music.

Anyway, the next day I left home (again, no internet connection in the street) and the albums were there, I listened to them without an internet connection.

Left the office at night, tried it again and, oh boy, the albums were empty again.

This has happened for the last couple of weeks now. I already contacted Spotify though Twitter and they've asked me to download the app and remove any kind of "delete cache" app. No changes so far.

I've noticed that if before leaving a wifi connection I open the app, and then leave the place (therefore the wifi connection), the albums will be there offline; if I don't activate the phone nor open the app, it is most likely that I'll find the albums with empty content.

What do you think? Is it a setting on my phone that is causing this?

Thanks in advance.

Luis