Downloaded songs desapearing

[guithegood87]

So, as the title says my downloaded songs simply desapear with no apparent pattern ern. Already trobleshoot my phone and it solved for a time but days latter it happened again, I found a thread from 2012 where the solution was a repair from the moderator end.
My phone is an Brazilian Moto Maxx running android 6.0.1.

Thanks in advance.