Can’t connect to router

[Jakib]

I’m installing a nighthawk mesh extender connected to my xfinity router and the app is telling me it cannot connect to my router. It looks like it’s connected to my wifi tho

[plemans]

what "make it looks like its connected? 

What method of setup did you use? WPS, the app, or the installation assistant? 

What router model are you connecting it to? 

what actual model extender do you have and what firmware is on it?

If you log into the router and look under its attached devices page (or equivalent), is the extender showing up?