I am almost finished my first quilt! The longest UFO imaginable. The quilt top is applique on cotton background. Batting Hobbs Cotton/Poly mix, backing fabric 100% cotton (old bedsheet). Now, there have been sections of it where it has been almost impossible to get a needle through. 90% has been easy, able to pick up a needle full of stitches, but there were a few places that I was only able to get one maybe two stitches and had to pull it through with pliers. Even happened in spots within the same hooped up area of fabric. One inch away would be like butter, then a hand sized patch tough as leather. I am only quilting the background and not through the appliqued pieces. Is it a flaw in the batting?