Port forwarding with Arris G36 not working

I have my home network based on the TP-LINK router doing port forwarding just fine. Then I received a suggestion from Xfinity to upgrade my modem to get maximum download speed. They recommended the Arris G36 gateway, and I got one to replace my old modem and router. I configured my new gateway for the same port forwarding schedule. Now my network has access to the Internet but port forwarding does not work well. I used an online ports checker and found out that standard ports like 80, 443, 21, 3389, etc. are open. Although other configured ports like SQL ports are closed. Someone told me that Xfinity may need some additional port forwarding done to open those ports. Xfinity suggested using the Xfinity app to do that. I followed the instructions published on the Xfinity site to do that but ran into a problem. The app's Connect screen does not have a network section with Advanced settings. It shows this: