Not quite the same problem but with my friend's machine there was an issue with how the sensors for the Stitch Regulator were set. I could stitch in one direction just fine, but the other direction there was no stitching. I cleaned the pads, they were surprisingly dirty even though the set-up was pretty new, and reset/adjusted everything which solved our problem.
That machine is rather fussy about its bobbins and we have never been able to wind bobbins well on it. When we switched to a lighter weight pre-wound bobbin from Superior most of our problems went away.