If a site is misconfigured, and presenting more than one HSTS header, then securityheaders does not reflect this, and reports only one of the headers, with no indication that there are any more.
For comparison, SSLLabs will highlight that the server provided more than one HSTS header.
If a site is misconfigured, and presenting more than one HSTS header, then securityheaders does not reflect this, and reports only one of the headers, with no indication that there are any more. For comparison, SSLLabs will highlight that the server provided more than one HSTS header.