Are you sure you got the right foot for your machine? Check the shank you screw in the feet to. Lower the foot lever, then with a scrap piece of fabric, see if you can pull the fabric out from between the walking foot and the feed dogs. If it pulls freely out you likely have the wrong foot for the machine.
Can you get in touch with the company you bought from to see if they will stand behind it?
I don't always use my bar on the walking foot. I only use it occasionally so try using the foot without the bar, try moving the bar closer or farther away from the foot itself to see if it's hanging up on something.
Sure hope you can figure this out because it's the best foot in the world when it works right.
Hugs,
Sharon