I am not sure where goes wrong so that I have missing backup pin in second certification path:
Actually I am not sure why there is Path #2. Is there any way to fix it? Thank you very much for your help in advanced.
You only pinned all certificates in the second path. You must specify at least one backup pin. Right now your pins will be remembered only by browsers that trust "COMODO RSA Certification Authority".
Got it. Thanks for your information and help.
For my record, to get the backup pin:
You can also create CSR for the website, and use the base64 of the CSR as the backup pin.
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