Touch devices can’t find SSID using TP Link M4 Deco

I thought I would give my wi-fi a boost and bought a TP Link M4 Deco mesh system.

Plugged it into my BT Router and connected a few devices with no problem until I got to the first of my 3 SB Touches and found they can’t see the SSID from the Deco.

Tried resetting everything but to no avail. Also tried manually entering the details but no joy.

Has anyone else tried a Deco with SB Touch?

Any help much appreciated.

Cheers.