I compared our walking feet, and they appear to be identical. I wonder if you try taking out your needle, then attach the walking foot if that would work, that is what I had to do when I first got this machine and the walking foot - try that and see what happens.
Put the fork over the needle clamp first, then attach the rest of the foot. Replace the needle and see where it goes down into the bobbin area using the wheel on your machine, without using the foot pedal.