@Riley_S what gives the impression that I have two routers on the network? I didn't state that anywhere in the post. I only have the Deco.

The only reason I made the suggestion of a web UI was because it's asinine that if I can't get the inherent wifi the Deco uses to resolve correctly and my phone to detect it, it's basically a 300 dollar paper weight since the setup won't complete.

Seriously, who had the bright idea of an app as primary setup when webUI is 1000x superior since I don't need to rely on this piece of garbage to do what it's supposed to do. What if somebody buys this at the recommendation of TPlink, like my family did, and doesn't have internet available during setup? Probably just a way for TPlink to more easily harvest user data.

It feels like TPlink is trained to give non-answers, since you didn't really ask for any information in your reply and made wild assumptions based on very little information.

  @DecoSucks2 

he gave you that answer because that is what would happen if you had two devices acting as DHCP servers handing out IP addresses on your network. like Riley said, give us a better idea of your network map. using wifi only backhaul? ethernet? using the main deco attached to your modem via ethernet cable directly to the modems WAN port? who is your cable provider? model of modem? which Deco model? are they set up in accesspoint or routing mode? help us help you.

ive been using TP Link for years and have set up Deco mesh at my house, and both of my parents houses without any complication. i recently switched over to the Deco X50's but decided to go full Omada so grabbed some EAP-610's to replace them. never had any issues with TP Link.