No rush on any of this since my internet functions. Really appreciate your support.
I’ve been texting the AT&T rep. since it is their box and gave him this thread to follow since I’m quoting him. My internet searches show this to be a significant issue with the BGW320 so a resolution would be helpful to many.
He sent some Deco menu’s from what looked like a very old and different country. (Turkey) Nevertheless I got an idea what he was looking for. So I mapped out similar menus from my Deco. There are a ton of options, He believes I could change my ‘Internet Connection’ to a Static IP. Enter the relevant info and it should be able to bypass the BGW320 assignment. Just want to know what you think. I’ve attached the menu option layout.
Did a bit of looking last night. The TP-Link/Deco x20 manual is 140 pages. There’s a description of switching Operating Mode between Wi-Fi Router (current) to Access Point Mode. It’s the first item at the top of the Advanced section.
I believe this is the description of Option 2. So if worse comes to worse I could reset the BGW320 to default and change the Deco to simply an Access Point.
I would prefer not to simply for the endless options provided at my fingertips of the Deco setup. Many I have yet to explore.
Changing to a Static IP that looks back to the BGW320 outside address enabled the Outside Access in Plex. So it looks like it bypasses the AT&T assignment and thereby removes the double NAT. I’m assuming everything is as secure as it was with Xfinity since the previous modem was separate and not belonging to Xfinity. The router is the same and working as before.
Major thanks to @FordGuy61 who walked me through the steps leading to the solution as well as the AT&T rep. who made the suggestion once he became aware of the Deco’s options. Let me know if you have any other suggestions. Thanks again.