re: Why is this happening?

I understand that this is the same model blade you've used successfully before.  But, this is a heavy-duty ripping blade being used for a (sort of) crosscut of a small piece.  I always use a crosscut blade for doing something like this.

From the Freud overview of this blade:
Ideal For: Smooth, Fast Heavy-Duty Ripping. Depth of cut (3/4" to 2-3/4")

The hook angle of this blade is a whopping 20 deg.  A typical crosscut blade has a 10 deg hook angle.