Hmm, I'm here because my iRealPro (8.2.1 on an ASUS 7) just started doing the same thing ... not all songs showing on a playlist. The playlist name shows the right number of song, but the content shows fewer.
I tried deleting the playlist and rebuilding the playlist, but it did the same.
I tried creating a new playlist with a different name, same outcome.
I tried a full power-down and restart of the device, playlist still broken.
I came to the fora and found this thread, so tried 'shuffle'. iRealPro crash.
I restarted iRealPro and tried an alphabetical sort, but songs still missing.
I then immediately tried the shuffle again, songs still missing.
I closed iRealPro and opened the playlist to find _most_ of the songs present (13/16).
I tried shuffle again, crash again.
I restarted iRealPro, tried alpha-sort; crash.
I restarted iRealPro, tried shuffle; crash.
I restarted iRealPro, tried alpha-sort; crash.
... and some more ... now always crashes, now still only 13/16 songs.
I've sent a crash report with logs.
I'll now try backup/reinstall/restore.