EC2 inbound custom ip rule not working

I am trying to set up a testing website on EC2 which can only be accessed internally. What I am trying to do is ask every one to give me his public ip. (By googling the word 'ip') Then I add a rule to the EC2 security group. (Add a rule Type=All TCP, protocol=TCP, port=0-65535, source=[public ip]/32) However this doesn't seem work. They still cannot access the website.

For example, if I make the source to be "My ip", EC2 console populate it with my public ip suffixed by "/32". At this time I can access the website. If I just change it to "custom ip" with the same ip + "/32", I cannot access the website. Is there anything I am doing incorrectly?