MQ,
It sounds like you have it installed correctly. I went to the BL manual for the machine. Do you have one? If not, go to the BL site and there is a place to down load one for reference. Check in the Basic operations section. (starts page 55).
On page B-57 there is an explanation on how to adjust the amount of fabric going through the machine. It's in the settings function on your screen settings.
Is the black belt moving along when stitching? I know you can't stitch fast with the WF. Stitch about medium and a little less than medium. (if you can stand it). LOL.
Next, do you have a local dealer that you can take the machine and a sample so they can see the problem? Hopefully, they are close by and can help you.
Just trying to help you get it figured out. I love using that big foot for quilting and stitch all bindings too. Good luck!
Another option is to send an email to BL and see if they can help.