An update from ASUS on router troubleshooting:
During routine security maintenance, our technical team discovered an error in the configuration of our server settings file, which could potentially cause an interruption in network connectivity on part of the routers. Our technical team has urgently addressed the server issue and impacted routers should return to normal operation. If your device was affected, we recommend the following:- Manually reboot your router
- If rebooting does not resolve the issue, please save the settings file, perform a hard reset (factory default), and then re-upload the settings file (follow the directions in the https://www.asus.com/support/FAQ/1050464)
- If you cannot access the user interface to save settings or perform a reset, you can press the RESET button for about 5-10 seconds until the power LED indicator on the router starts to blink, which means the reset is completed. https://www.asus.com/support/FAQ/1000925/#m2