i m not open some website through pfsense proxy server but i m able to open the same site through natting system. those website are along with some port for example http://citpltos.co.in:91
how to allow the port in pfsense proxy
Access your pfSense shell,
Edit squid.inc file ;
Find safeports acl line and add your port numbers ;
acl safeports port 21 70 80 97 8888 etc.