XFi Advanced Gateway - not getting WiFi 6

My understanding is my Xfi Advanced Gateway (XB6) supports WiFi 6. I've confirmed the driver on my computer also supports WiFi 6 - however when I look at my WiFi properties - it's showing that I'm on Wi-Fi 5 (802.11ac).

I went into the Xfinity Admin / gateway settings (Gateway -> WiFi) and saw the 'Mode' is set to 802.11 a/n/ac - and there's a dropdown there to change it, however it's greyed out - so I'm not able to change it to 802.11ax (WiFi 6). Anyone know what's up and/or how to fix it? I saw on a post a year or so ago that Xfinity was coming out with a firmware update to allow WiFi 6 - but again that was a year ago so I'd assume that should have been out by now.

Thanks!