Problem with Port Forwarding for Router BGW210

I am trying to set up port forwarding for my ATT Router Model # BGW210. 

Here is what I have tried so far:

• Followed the directions in this link: https://www.att.com/esupport/article.html#!/u-verse-high-speed-internet/KM1215101 
• Updated the router's firmware to a newer version.
• Setup a packet pass rule for TCP connection to destination port xxxx
• Multiple other connection changes using the routers interface.
• Reset the router to its factory defaults and then tried many of the previous steps.
• Tested the port I configured in the firewall using: https://www.yougetsignal.com/tools/open-ports/
• Reviewed the routers firewall log and found that connections from the aforementioned port testing tool were being blocked. (Log stated TCP connection was blocked with reason of "General Discard".

This is an issue with the BGW210 router and/or AT&T's network configuration. I have set up port forwarding many times over the course of my career and I have never had this much trouble with something that should take 5 minutes. I call tech support and they tried to get me to pay them $49.00 to resolve the issue with their router.