I have an Amazon Kindle with the Spotify app. It's a recent model, but not the newest. One of my playlists is 152 songs, but the kindle app says its only 129. On my phone, all 152 show up, so it's not local files from my laptop that I'm missing. I've tried logging out and logging in again, removing it from my synced devices in my account over view page and resyncing it, and deleting the app and reinstalling it, but nothing is making it show up.
If I make a new playlist or add songs to other playlists, they show up, but after about 130 songs, they stop showing up.