No method of setup is working. The device is physically touching my router. My passwords are correct. Both the device and wifi are detected by both my phone and my desktop. But every time I attempt setup I get an error during the "apply my settings" stage. Using WPS doesn't work, either.

I've tried both methods with and without directly connecting the extender and my router via ethernet cable. Nothing works.

My router is direct from the cable company, Spectrum. It's a RAC2V1S 802.11ac. Is it too old?