With the following terminal command you can reset the balance in case it gets shifted. Make sure your headphones are connected and selected as output device. osascript -e “set volume output volume (output volume of (get volume settings))”
Is this on macOS? I‘ve had a similar problem for a while. The balance in fact sometimes changes itself.
Funny enough, we have had this comic in our operations office at my former employer. This was years ago but sadly it is still relevant as of today.
IINA does play albums with a neat playlist overview and cover image.
Apple seems to have implemented quite some measures to make alternatives to the AppStore as unpleasant as possible. Even europeans will loose access to stores if they are out of EU territory for undefined periods of time, as per https://support.apple.com/en-us/118110