Diagnosis
WPS (Wi-Fi Protected Setup) is notoriously flaky and insecure. On this router, a blinking WPS light usually means it's timing out because the handshake with your client device (like a printer) failed.
How to Fix It
Honestly, just don't use WPS. It's a security liability and often broken. Instead, connect your device manually: log into the router (192.168.50.1), go to Wireless > General, and note your network name (SSID) and password. Enter them directly on your client device. For devices without a screen (like printers), there's usually a workaround using WPS "PIN" mode or a desktop utility from the manufacturer.
If That Didn't Work
If you must use WPS, ensure you're activating it correctly. On the router, press the WPS button once—the LED will start blinking. You then have two minutes to press the WPS button on your client device. If the client doesn't have a button, you may need to select WPS from its software menu within that two-minute window.
Heads Up
For security, WPS is disabled by default on many new ASUS firmware versions. You might need to manually enable it under Wireless > WPS, but security experts strongly recommend leaving it off due to a design flaw that makes PINs crackable.