This is something that you can do with the desktop app, if you have access to that. To do so, simply click and drag the playlists to your preferred order. This order should sync to your mobile app as well.
Sorry that I couldn't be of more help. If you aren't continuously making new playlists, it's probably worth it to rearrange your playlists on desktop once so that they're to your liking. Of course, this becomes more time consuming and more of a hassle if you are someone that makes new playlists or follows playlists very often.