Orbi start up problems & Netflix / Prime download failure

The first step is usually to determine if the ISP device is "only a modem" or a WiFi/router/modem combination.

My sense from the description is that it is a modern combo device.

Trying to browse to http://routerlogin.net requires that name to be translated into an IP address, which is going to depend on which device you are connected to (and how).

If there is a Windows computer available that can be connected to the RBR20 with an ethernet cable, you can do this:

Open a "DOS Window".

Type ipconfig /all

This will reveal the IP of the computer and the IP of the gateway, which is the Orbi.

Open a web browser to http://<ip of gateway> to be connected to the Orbi web interface.

Having two routers back-to-back is often a source of problems.  Generally, there are two recommended solutions:

• Have the modem be "only a modem" by placing it into "bridge" or "passthrough" mode.
  Disable all router and WiFi functions on the modem.
  Rely on the Orbi for every connection in the house.  i.e. do not plug anything directly into the modem excep the Orbi.
• Keep the modem as a router, but disable the WiFi function.
  Place the Orbi into access point (AP) mode.
  The ISP device will continue doing all the "router things", such as assigning IP addresses, looking up internet names, etc.
  The Orbi will handle all the WiFi connections.

Is this enough for a start?