Local files disappearing

[ilmater989]

I've had spotify premium for more than a year because i want to store offline files for car trips.  I will download albums locally and all will be great - for about 2 weeks, then every single thing i've downloaded is gone.  So, i must be using more devices than i'm allowed, right?  Except its just my wifes phone and my own listed as my devices used.  Why is my local content disappearing??? This happens on both devices.

[ilmater989]

Both are android devices fyi