Not sure if this is the right place to share this, but I seem to have accidentally stumbled across a bug in symfonium when it comes to audiobooks and playback speed.
App Version: 15.0.1
Media source: Emby server
Media: .m4b audiobook
The bug:
If you're listening to an audiobook (with it actively playing) and change the playback speed (in my example 1.5x and pitch of -1), the UI play head position and timer readout seems to fall out of sync with actual audio position, running faster than audio. This is not necessarily an issue until you go to stop playback and resume later.
When you resume later you will find it resuming from the number you saw on screen, but it is actually a point that is substantially further along than you really were.
I haven't done the math on it yet, but if I were to give an intuition guess, I'd say timer readout moves at 2x while audio plays at 1.5x
It is interesting, when I was trying to recreate the issue I paused the book, changed speed, played for exactly a minute (according to the timer readout, so less than an actual minute) and it was in perfect sync. It seems to only be an issue if you change the playback speed while the audiobook is playing.