I did a hard reset and still have the same issue. It happens when disabling one of the wireless bands (I disable 2.4ghz), when I enter in mac addresses for mac filtering, when I switched from the default 149 channel to auto. It says "Applying Changes" with the spinning wheel and "Waiting for router" next to it. "Waiting for Router" becomes "/etc/config/network" and stalls there. If I look on the router screen itself, under the status screen, my connection turns to "Internet Disconnected". Interface on the router is not frozen, but ssh/web ui are inaccessible and I have to reboot to get things working again.
EDIT:
To add some more info, I have the router in AP Mode. If you want the system logs, let me know.