Rings of Change help please

Hiya all,

How are we today? I am making this blanket for my daughter, am up to Round 51b (crocodile stitch), but laying the blanket out it is not sitting flat at all, almost like the last 20 rows are too tight or something, yet my gauge hasnt changed, neither has my hook or yarn. So I guess my question is, did this happen to you when you made this? Does it flatten out with washing/blocking? I am beginning to really worry that I have totally wasted a lot of my time on making this :/

Any help at all is greatly appreciated. Thanks so much!
KJ