Djs I once got confused with clicking the song title and it going into settings.
When it does this, Do you get the tabs along the bottom: History, Playlists, Songs, Settings?
If you're on Settings, it would jump between the song's lyrics and settings when clicking the song title.
Not sure if your problem could be as simple as this, but it caught me out recently while my brain was busy solving some other problem.
With the new updates, you have to pay attention to the separate volumes for song and playlist. After going through Peter's advice, do you get the same problem playing through the iPad's speaker?