Whenever I try to erase, move or edit a note, I can’t because the highlight is below the note, so I can’t select the note. I’ll post a picture if I can.
it happens to me too 
I know that Glitch, and is annoyng, but usually is only a visual problem
Try resizing the window. Hope it works.
I know how to. It mostly happens on low or high notes, or too many loud notes, like too many metal guitars.
Solution:
[details=Click to expand]
click on the note, if it just sits there, it probably will delete the next time you play the song, you want this to happen. Then pause the song, get the instrument you want. and BAMMO problem solved, it took me a while to fix this problem too…[/details]