You may find that sites using IPv6 fail to load after installing NGINX with Reverse Proxy (ea-nginx).
NGINX with Reverse Proxy (ea-nginx) does not yet support IPv6. There is an existing case (ZC-5555) to add support for IPv6.
There are two possible workarounds.
Remove the IPv6 DNS records for the sites.
How to edit a DNS record in the DNS Zone Manager
yum remove ea-nginx