Godaddy wildcard certificate "SEC_ERROR_UNKNOWN_ISSUER"

I am using a wildcard certificate from GoDaddy in my GitLab server. git clone fails with SEC_ERROR_UNKNOWN_ISSUER. I combined the intermediate and root certs with original cert and enabled the nginx[‘ssl_client_certificate’] = “/etc/gitlab/ssl/xxxx.yyyy.info.combined.crt” option, still it didn’t help. I can’t use letsencrypt cert as the server cannot be accessed from the internet.
Please help me to fix this.