I’m having to add the newest Sectigo root cert manually to my check_mk installation because it can’t auth against our LDAP servers that have renewed Sectigo certs. It works for about a week and then it disappears again. The file I’m editing is “/omd/sites/mysite/car/ssl/ca-certificates.crt”.
You need to install the new cert inside your Linux system. The file “/omd/sites/mysite/car/ssl/ca-certificates.crt” is a copy of the system cert file plus your own installed certs inside the site.
There are no certs distributed with CMK. It is better to check with your distribution mailing list if you can make a bug report there.