Sounds like your top tension needs to be just a smidge tighter, some machines won't let you adjust in tiny amounts. Or you can try changing thread colors so they are the same top and bottom, sometimes a light gray will work good on blue and white fabric. Good luck, but remember that FMQ is very addictive and it doesn't have to be perfect. I suggest that you make some small quilt sandwiches to practice on and start out by writting your name, over and over, A lot of FMQ is muscle memory. When I want to learn a new design I draw it on paper several times and then practice on sample quilt sandwiches. My favorite part of quilting is the free motion quilting. Hugs