Cannot set hardened_site criteria to 'Met' for the project 1614

[rameshmiyer]

We are unable to set the hardened_site criteria to "Met" for our project in https://www.bestpractices.dev/en/projects/1614/ Each of the URLs listed there have a A rating from securityheaders.com, but we get the message "One or more required security headers is missing".
Can the message indicate which header is missing and which URL it is missing from? Is an 'A' grading sufficient even if a header is missing?

[TonyLHansen]

There are three URLs listed in the response, one of which is GitHub.