My Spotify keeps deleting offline tracks from my OnePlus3 phone running Android 6.0.1. The phone is not rooted and does not run any custom rom.
I have looked at my offline devices and can see two android phones listed. One was last updated 03/10/2016, and the other 05/10/2016. I only have the phone logged into one phone so this cannot be possible.
Does anyone know why this is happening? I am travelling at the moment and was hoping to rely on Spotify for my music, but this does not seem possible.
The same device being listed twice can indicate that either the SD card was unmounted or that the sim card was changed. I believe that in both cases, spotify sees the phone as a new device and will remove access to already downloaded music.
Ah yes, dual sim phones seem to have issues with spotify. Try searching the community for "dual sim".
All I can suggest is that you use the online contact form and someone at Spotify can help get this sorted. If you get an automated response directing you back to the community or to the help pages, please reply to it by email and you will hear back from one of the team shortly.