@Jamie, why are we using the SSLCACertificateFile directive to provide the intermediate certificate to clients!? That directive is meant only for client certificate authentication, not for serving intermediates.
Besides, we don’t need to include the intermediate certificate these days, and definitely not via SSLCACertificateFile. Older Apache versions used SSLCertificateChainFile, but modern ones (version 2.4.8 and up) expect both the certificate and the chain to be in SSLCertificateFile, like in ssl.combined.
We definitely need to fix this!
If anyone is seeing this issue, just remove those directives by running:
sudo find /etc/apache2 /etc/httpd -type f -name '*.conf' 2>/dev/null -exec sed -i '/^[[:space:]]*SSLCACertificateFile/d' {} +