Originally Posted by Lisa_wanna_b_quilter
My suggestion is to slow down. I've had the same problem a dozen times and tried everything under the sun to fix it. When I quilt more slowly the problem either goes away or at least gets better. Apparently, my machine does not have to go 100 mph to FMQ well.
This suggestion made me think of another possibility .... with the speed, are you perhaps moving your fabric faster than the machine is stitching, and thus, causing tension which then is giving a reason for the thread to break?