i really don't like using sprays---i pin- lay the backing out smooth- but not stretched- then the batting nice and smooth- not stretched- then the top=== pin at least every 4" in a grid (with any luck not where your quilting lines will be-if you can lessen the pressure on your machine foot- or use a walking foot-
and perhaps lengthen your stitch length- if your stitches are really tiny that can cause it too.
take it slow and steady
that's all the tips i can think of at the moment...
personally i hate using the walking foot- but my machine has settings to change the (weight-pressure) of the foot on the fabric-