Hello

I have just installed a Deco M4 twin set, one of  which is plugged in via my existing Vodafone router, but when I switch to Deco Wifi (rather than Vodafone Wifi), I get 30% slower speeds than by just sticking with the original router. I have tried turning off the Wifi function on the router, but that makes no difference.

Am I doing something wrong? 

I would be grateful for any suggested fixes before I send the Deco kit back!