I'm using Pinnacle Studio 23 Ultimate.

I have a movie that is 12 minutes in length.  Source footage is two 4k cameras that recorded a 2.5 hour baseball game.  The footage was all edited with MCE, then the MCE was placed on the timeline and additional work like titles, transitions and a Scorefitter tracks were added.

When I play the final version via the Timeline, I hear the entire scorefitter track all throughout the 12 minute video.  However when I export the movie it gets to about the half way mark and the Scorefitter track goes dead.  The music doesn't come to a natural scorefitter ending, it just cuts out and is gone for the rest of the movie.

I then went to the timeline, moved the ScoreFitter music so it ended where it stopped playing on the exported version, then added a second song on the scorefitter track to cover the 2nd half of the game.  I then exported the project and when I played it back there was ZERO scorefitter music. 

Is there a known issue with ScoreFitter?

Is there a way to tell Scorefitter to re-render their track? 

I'm not aware of a "length limit" that would stop a Scorefitter song partway through (I just tried an audio-only export of a 12 minute song and it contained audio right the way through). I recall the only issue I experienced with longer songs was that the "arrangement" of some could become "stuck in a rut" and repeat the same few passages of music instead of re-using other variations from elsewhere in the song.

The issue might be with Studio keeping track of temporary render files if you had made a lot of adjustments to the music before arriving at the "final" music choice and length.

You could try deleting the render files (Control Panel -> Storage Locations" -> Delete render files) to force a complete rebuild of the Scorefitter music (of course if you're using background preview rendering (optimization threshold > 0) that would also remove any preview render files for video too - but they aren't needed for the export, so you wouldn't have to wait for all the yellow/brown preview lines to vanish before going to export

Alternatively, you could try working around by making an audio-only project containing just the Scorefitter music; export that as a MP3 or WAV file and use that in the the main movie.

HTH
Richard