I have an Archet A10 with the latest firmware. Once or twice a week I will lose one of the frequencies (either 2.4 or 5). I have separate SSIDs for each, I'm not using the single SSID, auto connect option. Switching my phone from one to the other fixes the problem but that only works for a phone - I can't do that on other devices. Note that the 'failed' SSID is still being broadcast and I can connect to it, but there's no internet available.

In addition, I can't log in to the router through Tether nor a browser pointed to the IP address. Again, internet may be functional but the router won't respond. I can ping it from multiple devices. A power cycle is the only way to regain control. 
 

Any ideas?