@anqu 

Update:

Hello, thanks for the update.

Firstly, Deco device is a network device or system, just like your PC, it will need to resolve or send the DNS request to one or several of those domains or websites, such as the domain names mentioned here to detect the online connection and it is part of the green LED status, which means the internet is good on the system, only when Deco resolves the outside website successfully, can it display a solid green light (even when it is in AP mode). You may also check some other network devices from other manufacturers, they should be working like this and behaving the same.

Secondly, Deco only resolves the DNS domain names but it is not actually connecting or pinging to the websites, so please don't worry about the traffic or data usage in your network, it won't be much.

Additionally, different regions may have a different network or DNS domain limitations/restrictions, so it will try to resolve different domains based on your region, you may block some while it will connect to the others in order to keep the connection alive. If you block all the domains from your network, the Deco system will display a red light.

May this answer your inquiry.

Good days.