Do you have a flat surface for your machine, recessed into a table or an extended flat surface around your machine? If not, that can make it very difficult to do any quilting or stitch in the ditch. Just too hard for the machine to pull a quilt sandwich up hill.

I agree with those who suggested a walking foot. It can make a world of difference in multiple layers.

Thanks for all your thoughts. No I haven't been using my walking foot. I will try that.