OOD 1.8 and SAML2 and ADFS authentication

I am installed OOD 1.8.12 on CentOS 7.8 and configured it to authenticate using mod_auth_mellon using the provided instructions. https://osc.github.io/ood-documentation/latest/authentication/adfs-with-auth-mellon.html. I am getting an error when I try to authenticate that the post URL does not exist. The ADFS authentication appears to be successful. I am wondering if I missed something on the OOD side. I get a 404 error with this request https://xxxx.xxx.xxx.org/mellon/metadata/postResponse.

The apache log provides this information.

Endpoint “metadata/ls” not handled by mod_auth_mellon.
[Mon Sep 28 11:05:19.781119 2020] [auth_mellon:error] [pid 143499] [client x.x.x.x:56253] Endpoint “metadata/postResponse” not handled by mod_auth_mellon.

/opt/rh/httpd24/root/etc/httpd/conf.d/auth_mellon.conf

MellonCacheSize 100
MellonLockFile “/run/httpd24-mod_auth_mellon/lock”

MellonSPPrivateKeyFile /opt/rh/httpd24/root/etc/httpd/mellon/mellon.key
MellonSPCertFile /opt/rh/httpd24/root/etc/httpd/mellon/mellon.cert
MellonSPMetadataFile /opt/rh/httpd24/root/etc/httpd/mellon/mellon_metadata.xml
MellonIdPMetadataFile /opt/rh/httpd24/root/etc/httpd/mellon/idpmetadata.xml

MellonEndpointPath /mellon
MellonEnable “auth”

My guess is mod_auth_mellon is not configured correctly but I am not sure where to start to debug this. What should apache return for /mellon/metadata/ls and /mellon/metadata/postResponse? Any help is greatly appreciated.

Thx,
Brad