Thanks for the post! I too have been wondering... I'm going to try your settings. 5GHz-2 for me will not allow me to change it. It's hard coded for AC Only... I'm running Firmware Version:3.0.0.4.380_7378.
That got it! Thanks! The Firmware Restoration tool doesn't work, it still shows it's not in rescue mode... I didn't think to try to access it directly.
Every since upgrading the firmware to 30043803479 I've had connection issues when I'm away from the router. I think it's an issue with it switching from the 5GHz network to 2.4GHz.
This was never an issue with the old firmware.
I downloaded and extracted firmware version 30043789529 for ASUS...