AT&T fiber gateway. Moderate NAT type, UPNP not supported. Xbox series S

I have seen several related posts to this but it seems for most people these issues occurred immediately upon installation.  For me I had faster/higher performance gaming quality for a year and a half, both on WiFi and with a direct Ethernet connection to the gateway.  But over the past few weeks I have still had otherwise great internet but horrible and unplayable connection to multiplayer platforms.  Which is when I saw the settings issues included in this inquiry’s title.

I saw that UPNP is not available for this product and even attempted to allow for my console and game of choice (COD) to have more direct access through the gateway firewall settings but to no avail.  I had temporary luck with manually altering the port selection within my Xbox for the Wifi connection but my NAT and UPNP issues returned soon after each of these port changes and now no alternate ports I select offer an “open” NAT type.

I also did a factory reset on both the router and my Xbox with no improvement in the NAT/UPNP settings or gaming quality.  I also saw a few postings online which suggested IP forwarding for a specific device but was not able to figure this out successfully.  

So my question buried within this novel is how can I return to the glory days of one month ago when I made fun of my friends trash multiplayer connection.  Or if I am simply doomed to this horrible connection myself as a form of karma for my many “time to switch off of the $5 Walgreens WiFi comments”.