How to block visitors from particular country with nginx and GeoIP Module

Question

I want to block a particular country's visitors to access my website www.mainwebsite.com through Nginx and GeoIP Module.

First I tried on www.test.com. What steps I followed on test website,www.test.com, before trying on www.mainwebsite.com

1. Installing GeoIP:

sudo apt update && sudo apt-get install geoip-database

2. Check GeoIP Module is installed or not:

nginx -V 2>&1|grep --color=always with-http_geoip_module

3. Download the GeoIP Database:

sudo mkdir /etc/nginx/GeoIP/

Placed GeoIP.dat file to /etc/nginx/GeoIP/ location.

4. Configure Nginx and Virtual Host. sudo vi /etc/nginx/nginx.conf

http{
##
# Basic Settings
##
      geoip_country /etc/nginx/GeoIP/GeoIP.dat;
      map $geoip_country_code $allowed_country {
        default yes;
        IN no;
      }

}

Save and exit.

5. sudo vi /etc/nginx/site-available/test.com Added the map line in starting outside of server{......}

map $geoip_country_code $allowed_country {
 default yes;
 IN no;
}

After that, inside server{......} setting, add the IF condition.

if ($allowed_country = no) {
     return 403;
 }

Save and exit.

6. Reload and restart nginx

sudo service nginx reload
sudo service nginx restart

So www.test.com is directly hosted on Ec2 instance test-server-01 with public Network/IP, Blocking worked and users were not able to access from blocked country.

www.mainwebsite.com is hosted to classic load balancer and ec2 instances are attached to classic load balancer.

For testing, I created 2 replica server of test-server-01 server and created new load balancer and attached both replica servers behind the load balancer and pointed www.test.com to new load balancer. But Geo Country blocking didn't work so I added 2 below lines above IF condition which (If condition) is mentioned in point 5, then blocking worked.

real_ip_header X-Forwarded-For;
set_real_ip_from 0.0.0.0/0;

Now I followed the same steps 1 to 6 for www.mainwebsite.com and made the changes in nginx.conf & /etc/nginx/site-available/mainwebsite.com but country blocking didn't work.

I have a doubt here that, for www.test.com, the contents of /etc/nginx/site-available/test.com and linked file /etc/nginx/site-enabled/test.com are same.

But for www.mainwebsite.com, the content of files /etc/nginx/site-available/mainwebsite.com and /etc/nginx/site-enabled/mainwebsite.com are not same.

/etc/nginx/site-enabled/mainwebsite.com has some extra contents like: Outside of server{} block-

# Expires map
map $sent_http_content_type $expires {
    default                    off;
    text/html                  epoch;
    text/css                   max;
    application/javascript     max;
   ~image/                     max;
    application/font-woff      max;
}

and inside the server{} block.

    server_name  www.mainwebsite.com;
    rewrite ^/blog/blogs$ https://www.mainwebsite.com/blogs permanent;
    rewrite ^/companies https://www.mainwebsite.com.com/company permanent;
    rewrite ^/events-2/* https://www.mainwebsite.com/events permanent;

Is this actual reason that's why country blocking is not working? Or there can be other reasons? Please help me out.