Thank you for your response. Yes, I am using ELB and those 2 IP addresses are the ELB addresses.
The only changes I made was to disable access to xmlrpc.php and had removed the registration on the website (added NOBLOGDREDIRECT and later removed it). No changes were made on ELB. On ELB I had port 80 re-directing to 443. However; to debug this issue, I have removed that redirection. Even then when I try to hit port 80 with HTTP, the request is getting redirected to port 443. I do not have any configuration enabled for HTTP to HTTPS redirection on Apache configurations.
Yes, I had followed the guides you shared while configuring the site, except for HTTP to HTTPS redirection. I do not use the domain mapping tool anymore.