DIAGNOSIS: The printer's stored network profile is for the old router's SSID or security settings. It can't negotiate with the new network.
FIX: Re-run the wireless setup wizard from the printer's panel. Press the Home button, navigate to Setup > Wireless LAN Settings > Wireless LAN Setup. Let it search, select your new network name, and enter the new password. The connection light should go solid blue.
IF THAT DIDN'T WORK: Your new router might be using a band (like 5GHz-only) or security protocol (WPA3) the printer doesn't support. Temporarily set your router's 2.4GHz band to WPA2/WPA3 mixed mode or WPA2, connect the printer to that, then try.
HEADS UP: The WF-2960 does not support WPA3-only or 5GHz-only networks. It must connect to a 2.4GHz band. Also, ensure you're not using special characters in your Wi-Fi password during setup.