So, I went back to a 90/14 quilting needle, which is the first needle I was using when I started this nightmare, and it's working better. BUT I'm not currently encountering the bulky seams that seem to create so many problems. If it starts choking and thread starts breaking again, I will try an 80/12. Maybe the smaller needle will pierce the seam more easily and grab less. I think you are right about the thread/needle combo. With so many variables, it's really hard to double shoot. I always stitch on a practice block first but it's just a muslin sandwich, not pieced with bulky seams, so it's not always a good indicator of how all will work on the actual quilt. The good news now is that, if it works sometimes, it's probably not my FMQ itself. Not that it's great, but the struggle is probably teaching me more than I realize at the present time. Thank you for your help!