Since I've bought this router I have same problem and last year support has temporarily solved problem by installing at that time "experimental" firmware as they told me.

I've bought three days ago this router and I've put it behind UBEE cable modem/router which is in bridge mode. Router seems to work OK but I'm unable to login via admin page nor via Tether app. When I press Log In on the page, cursor is spinning for 10 seconds and then stops but doesn't log me in. Similar is with Tether App. When I switch router off and then on I can log in but after short period (~10-20min to few days) again I have same behaviour and I'm unable to log in.

Does anybody had similar problem?