Gateway XB8-T

Have used numerous XB8-T models and for some reason this time only the app under wifi equipment then advanced settings the option for WiFi Band Selection isn't an option when it has been an option with previous XB8-T gateways. 

Question #1)

Anyone have any idea how this could happen with a Xfinity Gateway XB8-T model not having the option to select WiFi Band Selction when previous XB8-T models had that option?

Also using an wifi analyzer app and everytime restarting the Xfinity gateway it puts my network back on the same bad channel all the time for months now. Numerous techs have come out only to say above my pay grade as long as you have internet working.  The XB8-T used to would allow me to change the channel when on a bad quality channel but one I have now doesn't.

I restarted gateway because my network was on a bad quality channel for my network and also sharing with 4 other networks and one of the networks was red, security was open.

I restarted gateway a 2nd time and it put me right back on the same bad quality channel but this time sharing with only one other network.

Question #2)

Anyone have idea why when restarting the gateway why it puts me back on the same bad quality channel but sharing with different network names each time restarting the gateway?