> why the D-Link (at friend's house) worked fine for a week, but now it cannot connect The D-Link now reconnected again. The Archer has never connected reliably.

Sorry, which options do you mean? I mean this terziyski : https://community.tp-link.com/en/home/uc/info/991492 . But I don't think there's a way to ping someone, unless you Reply to his message....

@Eric_Le_Grompf Previously the D-Link (in my house: primary) and the Archer (in friend's house: secondary) worked without any problem, each providing WiFi in the respective house There's no WiFi...

@Eric_Le_Grompf Thanks a lot for your advice! It's complicated for me: although I'm in IT, my networking knowledge is rather basic. Before trying to implement it, could you please take a look at my...

@David-TP I attached an old D-Link router to the main Deco and it worked like a charm for a week: Then the connection became unstable and after restarting the D-Link, it cannot connect anymore: As...

@David-TP Sorry, cannot do this. The main Deco is on floor2, where the internet wire is incoming, and the extra LAN is outgoing to my neighbor. The secondary Deco is on floor1 (the living room), and...