RADIUS server is not responding. How does it work, and how can I bypass?

Question

First, let me set the stage here. I am in a short-term apartment rental in a building that offers wifi access (through a provider) for $30/month.

This service operates a lot like a hotel wifi service. I connect to the wifi network and when I try and access a webpage, a splash authentication page appears at 10.60.20.x. For about 6 months, this service worked fine, but for the past three days I have been receiving an error message "RADIUS server is not responding" when I try to authenticate to the network.

My understanding of the normal process flow is:

My computer connects to Router
My computer makes an HTTP request
Router detects non-authenticated MAC address and sends My Computer a response page (10.60.20.x/login) with a login form (username/password)
I submit the correct login details, and the request form is sent to a RADIUS authentication server
The RADIUS server authenticates me with these credentials and adds My Computer's MAC address to an "authenticated" list
I can now access the Router and browse the web

In my current situation, the process seems to be failing at step 4, with the RADIUS authentication server being unreachable. The wifi provider has not been answering my phone calls or responding to my emails, so I am wondering how this process works, why it might be failing, and if there is a workaround.

Why it might be failing

As for why I am seeing the error message outlined above, a non-responsive server indicates one of three things to me:

The server is shutdown
The RADIUS process is not running
There is a firewall rule blocking communication from the Router to the RADIUS server

Is there a workaround?

I came across a video guide that demonstrates AAA authentication bypass. The general idea is that I would spoof My Computer's MAC address to replicate the RADIUS server MAC address, and then use My Computer to validate My Computer's access to the network:

How to Bypass AAA Server

However, this guide seems to omit a few details:

How do I identify the IP address of the router?
How do I identify the IP address and MAC address of the RADIUS server?
Is this workaround possible if the RADIUS server is offline or inaccessible?

What began as frustration with the non-responsiveness of my internet provider has turned into an interesting mental exercise as well as a desire to understand how all of these networking components work together. I am very interested to see people's responses on this matter.