I had that problem once with my walking foot. Next time I put it on, no problem and none since. Did not look closely but it could have come loose. Wish I could help, but don't even know why mine did that. Try it again on some scraps .

same problem
 

I have the same machine and the same exact problem. The jumping completely ruined the quilt I just finished. I took off the foot, made sure it was clean and free of debris, made sure it was installed correctly and everything was as it should be. But it would still jump. I gave up on it and used my regular foot, but it didn't keep the layers together correctly. I was so dissapointed. It worked great for half my quilt and then started acting up. Tried it again on another item a month later and worked great then started messing up again as well. I am so dissapointed in the item. It came as part of my machine from amazon so I don't know how to return just the foot. I guess I'll have to go buy another one, but quite frankly I don't know if I want to waste my money on it if it's going to be a crappy product.

Did you ever find a fix to it? I'm starting to think its a problem with not only the foot but the machine as well since we both have the same machine.

Welcome to the quiltingboard, rearea1222. Hope both of you can figure out what happened.
HAPPY NEW YEAR.