It's quite common that non-business internet service will block incoming common ports. Meaning if you did not request something on port 80 you will not get any traffic on port 80 to your home router. They have several reasons why they do this and they are for good reasons. As you found out you have to change the port, if UPNP is enabled it will update the firewall rules to allow a connection in from the outside. I have found the firmware to be quite buggy. I have had to press the reset button several times already.
You may also want to consider getting DDNS (Dynamic DNS) service that way you don't have to memorize your IP address (which will change from time to time if you are running this from your home).