It seems like this is a Let's Encrypt bug, because I ended up with wrong intermediate certificate in the fullchain.pem file. Please close this bug.
** Changed in: ca-certificates (Ubuntu) Status: New => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2082625 Title: Let's Encrypt Root CA is missing To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ca-certificates/+bug/2082625/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs