Is there any way a "Failed to Connect to Master Server" error can happen other than the master server being down?

First off, I realize that the unity provided master server is for testing only and is not always online, but I'm slightly concerned that the last few times I've tried to test my networking (all on different days in the past week), I have been getting errors in my script which handles players connecting to one another via a master server. Yet in the 10+ times I tested networking before this week, it worked no problem.

Specifically, the error I am getting is "Failed to connect to master server at 67.225.180.24:23466"

I know this is most likely just the server being down on Unity's end, but I'm freaking out a little bit since I seem to be getting this error every time I try to test recently, and never once got it in past weeks. Is there any way this error can be caused other than Unity's own test master server being offline?

Testing with the following simple 2 line script leads to the same error.

 using UnityEngine;
 using System.Collections;
 
 public class TestMasterServerScript : MonoBehaviour 
 {
     void Start () 
     {
         MasterServer.ClearHostList();
         MasterServer.RequestHostList("TestGameServer789");
     }
 }