So, on my Samsung Galaxy S8 Plus using the latest available Google Play Store version of the app(for me at least), version 2018.02.14-release (Flipper version 1.3.6), after starting the app after having it closed, it displays the first song I play in my notifications and on my lock screen even after the song is done and in some cases skipped (from my notification bar).
The only way I've found I can get it to update to the correct song that works every time is by going to the app and pausing then unpausing the song. Sometimes skipping the song works as well, but not every time.
I'm like 90% sure this is a bug and not user error because I have every notification enabled, and my other music apps don't do this. However, I couldn't find a bug report page or anything of the sort.
If anyone does have a solution though, please let me know. This is super annoying when I'm driving and I can't see what song is actually playing on my car's display or the phone itself.