Cannot reconnect ex2700 to wireless network

Ex2700 has worked successfully in the past. Do to a router failure, cable company installed a new router. A colix gigaspire. I have tried multiple times to setup the extender after a factory reset. The end result is always the same, after going through the setup, reaching the stage where other WiFi devices are connected to the newly created extender WiFii ssid. At that point a www.mywifiext.com page requesting a username and password.l comes up. I can’t get past this screen using the default username and password.

This has occurred when setting up over a WiFi connection or using an Ethernet hardwire.

Any advice is appreciated. Is this extender toast?