Using Music Maker Premium (64-Bit) Version 31.0.3.26

I'm using the piano roll to create midi songs, but a single note always drops near the end of wherever the yellow bar is (the one that shows how many bars are in the song) (i.e. If I made the song 2 bars, then near the end of the second bar a note would drop. If I made a 16 bar song, then near the end of the 16th bar a note would drop instead) I have no idea what's causing this and would be most appreciative for any insight.