@Alexandre. Many thanks for this suggestion which I am implementing.

My problem that everything does NOT work fine with the Deco network on its own. That's why I got the provider's wifi working and that enables me to mirror my Apple products to the LG TV so I am not...

In order to sort out a problem with mirroring my Apple products to my LG G2 TV, I am now using my three Deco units in AP mode and have enabled the wifi on the modem/router provided by by network...