I have the following nginx conf file (shortened for the purose of this question) that is creating a cookie:

map $http_referer $setCookie {
default "";
~*somewebsite\.com "referrer=bl;Domain=.mysite.com;Max-Age=31536000";
}

server{

listen 80;

server_name mysite.com www.mysite.com dev.mysite.com;

root /var/www/mysite.com;

access_log /var/log/nginx/mysite.com.log spiegle;


add_header Set-Cookie $setCookie;

location /{
#add_header Set-Cookie $setCookie;
}
}

The issue is that if I click on a link on `somewebsite.com` it navigates to mysite, but does not create the cookie. If I then refresh the page it will create the cookie. Why do I have to refresh to have the cookie created and how can I get around this?