Coinciding with me updating my Mac from Sequoia to Tahoe, which might be culprit here, I've discovered that Longplay no longer plays albums in correct order. They always play in the same order, albeit not sequentially by the disc and track number. On some records the playback order looks like track title alphabetic order, on other albums it makes no sense to me.
The song title in the now playing screen and mini player is the one it should be playing, not the one that's actually playing.
I'm running the latest MacOS 26 beta 5, released earlier today with Apple Music library only. If you need help debugging this or to verify the fix, I'm more than happy to help, this is rather frustrating issue.