You can quilt that out: Dealing with puffy blocks on the longarm machine
The best solution for billowy blocks would be to take the quilt apart and adjust the piecing as necessary. However, that’s an option that isn’t a top priority once the borders are on and our minds are already on our next project. Instead we usually opt for the easy way out, convincing ourselves or the longarmer quilting for us that "it will quilt out.” Read out tips!