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, even when the speed is at 1. Any tricks to fix this slider issue? Thank you in advance.