Routers are working, though app does not recognize – Tenda WiFi Review

I have the AC1200 and, though the routers are working and useable and do a great job of coverage, I can no longer control them through the app. Perhaps there was an update and the AC1200 system is no longer serviced through the app? Difficult to find answers. So... app is a waste or phone screen real estate anything the moment.
Review by L. M. Peters on Tenda WiFi.