Hi. I recently had my machine serviced (by a certified APQS location) and since it came home, I've been struggling with stitch quality. My top stitches (mostly) look good but my back has the occasional loop or like a stitch pulled sideways like it is pulling the top thread down and over a bit, like it catches. My top thread is breaking quite often, the thread keep slipping out of the pigtail right above the needle, and occasionally it stops catching stitches at all for like an inch. I have changed my needle and rethreaded. I run So Fine on the top and super bobs on the bottom--pretty much the same thread types I have been using for 9 years. It is a little better when I stop using the SR but not much. the thread stops breaking but the stitches on the back still just aren't right. I would appreciate any advice or help! thanks.