I had that happen with a quilt but it was due to my piecing. It was the most difficult quilt have ever made! I used w&n batting. I laid the damp quilt on the floor, blocked it and put heavy books in the center. It was ok. It was for my grandson and wife. I don't know how it was after being washed. Btw it was a David and Goliath biblical pattern. Can't remember the actual name and author of the book. I think it was for a much more advanced quilter than I.
Lots of y seams.