The error you report here is clear. The web page for Failed Validation Limit says you get 5 failures per hour per hostname per account. So, you need to wait an hour.
But, did you fix the IPv6 problem in your other thread? Looks like you did not because I still see
Previous thread:
Please do not start a new thread for each different error message. It is more difficult for us volunteers to help if we can't easily see the history.