Songs stop altogether

[CorvoNero]

So I use a Kindle Fire, and every time an ad finishes playing my playlist won't continue it just stops. So when I click on a song it tells me to go ad free with premium. Also, after awhile of playing songs (maybe 10 to 20 minutes) the playlist will stop playing like with the ads except there are no ads, it just stops. Even then when I click on a song it does nothing. I have to turn my device off then back on again for it to work after both events. I've tried re-downloading the app, but it hasn't helped.