Regularly, a duplicate certificate of COMODO RSA appears on my keychain (Google Chrome?) and when I browse on a website which use a COMODO certificate. Google Chrome blocks the website. (Normal). I muse delete it and restart Google Chrome to be able to open the website.
How is it possible to have this kind of duplicate certificate?
EDIT: A website using a Comodo RSA Certificate: https://www.graylog.org/