Hi @alexc96
May we know how many seconds did you press the WPS button of the modem? Also, did you press the WPS of your extender right after the modem?
Did you try to configure the extender to connect to the WiFi network of the main modem manually?
Please provide us more information in order to analyze this further. (Make and model of the extender, troubleshooting you've done, etc.)
BasilDV
