In most of the Iron Maiden songs the "Set Difficulty" slider is not working. Sometimes it is stuck at 0 and all the notes on the screen come as if I had set this slider to 100%. Sometimes, on other songs, it is stuck at 100% and all notes come on the screen as it supposed to.  I can slow things down with the Speed slider but it takes much longer to learn this way.    A solo like Metallica's Hit The Lights becomes extremely hard to learn because so many notes come on the screen at the same time,