When using AG behind HAProxy TCP Load Balancer the AG receives the ip of the load balancer, not the one of the original client. HAProxy uses the "Proxy Protocol" (https://www.haproxy.com/blog/use-the-proxy-protocol-to-preserve-a-clients-ip-address/) to provide the original IP. Apache can read the original ip with the module mod_remoteip (https://httpd.apache.org/docs/current/mod/mod_remoteip.html) with the parameter
The original IP is very valuable for authorization and logging. We cannot switch to a L7 load balancer where the original IP would be added to the X-Forwarded-For header.