Just bought the
TP-Link Deco X10 (3-Pack) AX1500Mbps Whole Home Mesh WiFi 6 System,

I have successfuklly got it up and running but I want to check I have it right.

I have a Sky Broadband and TV account - so my Router is Sky and I have two SkyQ boxes.

I have connected Deco unit 1 via Ethernet cable to the router and set up Units 1 and 3 around the property.

I have set the nework name SSID and password to the ones I was using with the Sky router to avoid having to re-set the logins fot all my gear ... most especially the Sky boxes which get very shirty if they get confused !

That sums up the system at present and the Deco units are apparently doing their job well.

But I do wonder though that I now have two units transmitting the same info on the same channels (?) and they may interfere with each other ?
 

My next concern is that the router supplies 2.4 Ghz and 5 Ghz signals.
I am aware of the differences between the two systems and have previously left them alone to make up their own minds as to what style of WiFi they supply to my digital equipment.

However I thought I'd be clever and separate the two channels via the Sky router interface. - giving each a different name but otherwise leaving the settings as they were.

Sure enough I had two different WiFi addresses on my phone and computer and I could apparently choose which one to use

BUT the Deco app interface then only showed the 5Ghz connection and would not acknowledge the 2.4Ghz

(and at some point yesterday I lost the Sky TV connection too - had to go back to the start top get it back).

Ideally I would like to assign the 5Ghz connection to the two smart TVs that are in the kids rooms and use Amazon Firesticks (I believe the Sky TV uses 2.4 Ghz by design)

So, is it possible to assign the Deco Mesh to supply 5Ghz to the Smart TVs without tinkering with the Sky router settings. ?
Ideally I would like to turn the Wifi off on the Sky router and just let the Deco control the Wifi system but I know from my bad experience with the Sky TV yesterday that the SkyTV box doesn't like that.

I am well in over my head at this point having crashed the Wifi several times in my endeavours.

I'm sure there is an elegant solution to doing this properly but don't know how to go about it.
I'm pretty sure however that the two skyQ TVs in the house will have another nervous breakdown iif I turn off the wifi on the Sky router, which would be my preferred way of doing things and then controlling the system via the Deco app.

Any coherent responses and suggestions very welcome.