All of the above!
60, or even a 100 tooth blade, a little higher, with a backing board.
I also noticed that you cut 2 pieces.
More of a burn on the 1st piece, and it seems to be burning when you back the piece up.
I'm not a fan of the eraser hold down.
It's possible the blade is no good, and it might be pulling the piece back into the blade just enough to burn it.
I would try a few runs going all the way through, past the back of the blade, just to see what happens.
Figuring out how to do something you have never done is what makes a good challenge.