I switched from Spotify to Amazon Music about 9 months ago, and cancelled Spotify Premium as a result (due to price, not bugs). Amazon Music is
so much worse.
1. If you have no connectivity, the app will frequently get stuck in the offline state, playing the spinner indefinitely, even after connectivity has returned. I had similar issues on Spotify, but Amazon Music is so much worse.
2. I had Amazon Music eat my entire cellular plan's data monthly allowance in a day, after it seemingly got stuck in a loop trying to download the same podcast again and again. The podcast is unplayable when it gets in this state, even on perfect Wi-Fi, it just never starts playback. This has happened twice now (incidentally on the same podcast, but different episodes), even after deleting and reinstalling the app entirely.
The second bug is a deal breaker, so I've gone back to Spotify.