Nighthawk AC1900 R7000 router drops internet connection

I have the same or simular Problem. The R7000 drops in this case only 5G Wifi. I have Smart Connect disabled since it was in the GUI. So I have 2 SSID, one 2,4G another for 5G. So when 5G Wifi drops Internet connection, all connected devices are still connected, but have no internet connection, and when a new device will connect, it is not possible. When tis happens sometimes the internet connectin is very slow an unstable. When i change to 2.4G Wifi then there is the full speed available bake to 5G sometimes it is possible but the internet connection is again not ok. So in the past I reboot the R7000. Now I only press the wifi button on the router 2sec., wifi is off, again buttom 2sec. and wifi is up and on 5G everthing is ok, the Internet connection is without any issues. And now I also can reproduce the wifi drops. There is only one device in my set which causing these drops. iPad mini 1. Gen. When device runs on 5G on the R7000 and then I send the device to flight mode the R7000 5G wifi drops! This is crazy. Now I configured the device to only connect to the 2.4G wifi. No I have no problem. I am on 1.0.11.134. The GUI is also very tricky. I only can change the settings when connected by wire, changes when connected to the router over wifi in the GUI are possible, but after that I have strange errors, likevslow HDD connected to the USB and more other issues and the R7000 gets unstable. I can then load the last „good“ backup (but only wired connected to R7000 with the laptop) over the GUI and everything works stable again. After that I can changes the setting directly in the GUI and then it works, so i can save this to backup for future problems. This is my experiance with the R7000 in the last 2 years. And .42 was really the last perfect and stable version. Sorry netgear, this is not o good support. I told everthing to netgear, and thyvsaid to me, your router is too old and we do not make new firmware. But they make new firmware, security updates. Why? The router firmware is unstable. But for me I want to buy a new Netgear, stupid, but there are not so much good router on the market now. I testesd Fritzbox. Many problems. I want now buy RAX 120, but read so many articles here in community, that this firmware is unstable too, lots of reboots, every 2 hours or something like that. Soooo Netgear! Do your job. No the only possibility is to buy a Linksys MR9600. This is a good set of router. Hope somebody can check if you can reproduce my experiance with the router and give me a reply on that.