@AlanK47 I ran a channel analyzer with the 6 GHz option switched off and the XE75 was still broadcasting on the 6 GHz channel it was with the option switched on. Bottom line: If you turn the 6 GHz Network option to Off, the XE75 will still use the channel for dedicated wireless backhaul. If on, it will still backhaul, however, you can share it and use it with devices that use 6 GHz.

  @Accutronman 

It is the same with other bands: they are always used for backhaul.
You can only control what the Deco offers to the devices.