My netgear AX180 wifi 6 router unable to install with Spectrum all in one modem/router

What actual router do you have? AX1800 is a speed.

What spectrum modem/router do you have? 

Cascading multiple routers is a potential for problems. 

https://kb.netgear.com/30186/What-is-Double-NAT

You can help people to help you by providing the information suggested in this forum's header:

Subject (Include model number and brief summary)
Model (Recommended - Helps the community give the best answers)
Body (Include additional detail including model version, firmware, OS and environment where relevant.)

They are there for a good reason.

> My netgear AX180 wifi 6 router [...]

   None of that is a model number.  Look for "Model" on the product
label.

   With that datum in hand, you might try this radical concept:

      https://en.wikipedia.org/wiki/RTFM

   Visit http://netgear.com/support , put in your (actual) model number,
and look for Documentation.  Get the User Manual.  Read.  Look for the
LED descriptions and "Troubleshoot".  Pay particular attention to the
"WiFi LED".

   The RAX20 User Manual, for example, claims that "two buttons are
located on the front of the router", but seems to mention only "the WPS
button".  If there's also a Wi-Fi On/Off button, that could explain some
kinds of problems.

   Further reading might not hurt, either, but, with this quality of
documentation, I wouldn't bet on it.

> [...] with Spectrum all in one modem/router

   Also not a maker or model number.

   If you already have a "Spectrum all in one modem/router", then why
are you adding another router to the pile?  (There are reasons to do it,
but what are yours?)

   Also not a clear description of what's connected to what.  (Hint: If
a device has different types of ports, then "connected to device" is not
enough detail.)

> [...] The message [...]

   "The message" from what, when you do what?

> [...] is "unable to join the network Netgear48" also, it does not show
> up as an option on any of my devices.

   I'd expect something more like, say, "NETGEAR48", but only one of us
can see your product label.

   Worst case: Get a computer with an Ethernet interface, and try again
with a wired connection to your (unspecified) router.

> Really frustrated.

   Try to imagine what it's like for someone else to try and guess what
you have, what you're doing, and what happens when you do it.