@ArjanBr 

You can't do that with Deco mesh, unfortunately. If Main Deco is connected to Fritzbox router, there is a workaround I can suggest.

Hi @Alexandre.,

Thanks for your reply. Yes, the main DECO is connected to the Fritz Box. Can you tell me more about the workaround?

In the DECO, I can assign devices to a profile/family member. New devices aren't assigned to a family member, but they have access to the internet. I think there is some kind of default profile? Is it possible to config this default profile with no internet access?

Kind regards,

Arjan

  @ArjanBr 

As I said, it is not possible in Deco to block new clients that have correct WiFi SSID/password. 

The workaround is to switch Deco mesh to run in Access Point mode. See How to set up Deco to work in Access Point mode

This will transfer home network management to the ISP router, which is the Fritz Box in your case. Use "allow list" feature on Fritz Box to control who (which MAC address) has access to your home network. If this feature is not available on Fritz Box router, you may wish to get different router with strong content filtering features and "allow list."

With Deco mesh, these are only two feasible options: run Deco in AP mode with router doing all the work, or return Deco hardware if it is still under return policy and get WiFi mesh from the different brand.