XT9 - how to switch off the 5-1 GHz?

[2301]

For some time, I have noticed that all my devices connect to the mesh system (Ethernet backhaul) in the 5–2 GHz band (usually on channel 100, but sometimes on channel 108 when the router changes channels). I have 5 GHz Smart Connect turned on.
As the 5–1 GHz band in my area is flooded with over 40 Wi-Fi networks, and none of my devices connect to the lower band, how can I turn off the 5–1 GHz band?

 

[Crimliar]

How safe? Well you can try it and see, as you can easily switch back! You might be better off though if you were to manually set it to a channel (and use a thinner channel width) in the lower band that no one else appears to be using.
Give it go and maybe post back with the router model, and some anonymized graphs showing local Wi-Fi use!

 

[2301]

"...in the lower band that no one else appears to be using"
There are almost 50 always active WiFi streams. Dont understand "post back with the router model" Its XT9 as stated in posting title.
I dont want to polute the band with unnecessary stream.