Wi-fi Extender EX2700 won't connect to my new wifi network. Help! Please!

I bought the Netgear EX2700 Wifi Range Extender just a few months ago and it was working well, extending the range of my wifi signal in my house. I was very happy with the job it was doing.

This weekend I've changed the name and password of my wifi network. Despite trying to re-connect the extender several times, it is not picking up the new network name. I have not changed internet provider, simply changed the name of my network to a personalised one.

The extension name the extender IS picking up is the name of the router model itself (ASUS), however when I try to connect onto that extension network, it does not work on my internet browser.

I have tried to restore factory settings on the extender by putting a pen into the Factory Reset hole under the extender. That seemed to do nothing, despite several attempts.

If anyone can help / suggest where I am going wrong, I would be most grateful.