A college changed/corrected our FAFSA. how common is this?

thanks for your reply and further explanation. it makes me feel better that this doesn’t seem to be completely out of line. I will call the FAFSA helpline and see what they say.
What I find interesting is that the college that alerted me already gave us a full financial offer about a month ago, so they didn’t see any issues but another college obviously did. I will report back what I find out.