Security msgs after installing eax20

Installing an eax20 ax1800 to extend Wi-Fi and hit some dead spots in house.  Used the app, set-up seemed to go as planned, everything connected, but when I went to go log in to my laptop I got some messages that said there were security concerns and then it cut off my internet.  Went to go try my iPad, same deal, even weirder it took me to some net gear login page which led me to try and change my net gear account info (I didn’t). Same deal when I tried to access our Wi-Fi via my phone.  All devices show they are connected to network, but won’t allow me to access any content.  Had to disconnect to access help pages and get here.  Should taken me 15 min, I’m 3+ hours of frustration in.  Hoping it’s just some setting issues, but I’m not a techie guy, so I don’t even know where to begin..  Thanks!