Unable to access RBR20 with app or Browser

[Hendy]

Im hoping someone can help I've had this router for about 6 month now and I've had the following issues.  

1.  disconnected or dropped wifi signal.

2.  Over the last two days I have not been able to connect to the Orbi router either directly via the app (I have also tried the remote connection options) and also via a browser.   I get a message saying the router is offline even though all my devices are connected and have access to the internet and each other on my network.  Any help would be appreciated.  

[FURRYe38]

What Firmware version is currently loaded?
What is the Mfr and model# of the Internet Service Providers modem/ONT the NG router is connected too?

What is the distance between the router and satellite(s)? 30 feet is recommended in between RBR and RBS to begin with depending upon building materials when wirelessly connected. https://kb.netgear.com/000036466/How-far-should-I-place-my-Orbi-satellite-from-my-Orbi-router

Any Wifi Neighbors near by? If so, how many?

Has a factory reset and setup from scratch been performed since last FW update? 
Press the back reset button for 15 seconds then release. Walk thru the setup wizard with a wired PC or laptop connected to the back of the RBR. Try using a different browser, IE11, FireFox or Opera. Clear ALL browser caches. Find the wizard at 192.168.1.1

Something to configure after the RBR is set up...

Try enabling Beamforming and MIMO(MIMO may or maynot be needed) and WMM. Under Advanced Tab/Advanced Settings/Wireless Settings

Try disabling the following and see:
Armor, Circle, Daisy Chain, Fast Roaming, IPv6 and Set 20/40Mhz Coexistence to 40Mhz only. Set Short preamble instead of Long preamble modes. Save settings and reboot the router and satellite(s).