I have bought a new Deco x20 because I normally had to use my old Deco x20 on multiple places in the house. 
my old deco x20 gives strong performance. When I place the new x20 on exactly the same place, the app shows WiFi performance and the devices don't connect to the internet.  When I use the old one again, perfect internet connection.

i have reset the new deco, firmware is up to date. 
I hope someone can help me!!