R7000 2.4ghz not working but 5ghz is fine

Well, add me to the list. I did factory reset and rebuilt my router from scratch. I have simple setup too but have a nest thermostat and a wink home Automation hub that can only connect at 2.4ghz. Before the factory reset, my issue was exactly as described throughout this thread: perfectly reliable 5ghz and direct wire but 2.4 would just drop and devices could not connect. The devices still see the 2.4 and seem to pass it an acceptable password but keep waiting for ip to be issued. Also, I have tried turning on and off wifi switch  - no change in reliability. Rebooting router or toggling the wifi on/off hard switch on the router restores 2.4 functionality but only for a while. Issue occurs again usually within 24 hours. Fails for all devices. Also fails when 5ghz is disabled. Fails with and without password protection. Fails with one device connected, 7 devices connected, or no devices connected. Watching the netgear genie app after it fails, the 2.4ghz network disappears and reappears randomly and rapidly then suddenly settles down and is visible (but not usable) for several minutes then, bam, starts hopping in and out of existence again. I have witnessed this sane behaviour when scanning for wifi using two different smart phones. After rebooting router, 2.4ghz is always visible and connectable. And, when it works, it works great. Very good signal strength and very good distance. I have moved this router to a different floor of my house - exact same issue. When I drop the router and turn on my old trendnet I have no problems at all. I need 2.4ghz to run home Automation including my thermostat! For $200, this thing is useless to me, and I have spent almost 8 days and about 40 hours wasted testing it. Worse still, I was on with tech support and they told me I had a bed radio and needed to return it to Amazon. Uhhhh, sounds like everyone is having this issue so replacing it is not going to help. NETGEAR YOU ARE KILLING ME. please help