Postman variables are undefined - postman

Question

I've just created an account and am using web.postman.co. The online version. I didn't actually notice if the desktop client is still available
In my Postman workspace I've created an environment and there I've created a bunch of variables to match my vendor API auth request (Wialon). The values are pasted below:
[{"key":"hostname","value":"some.address","enabled":true,"sessionValue":"some.address","sessionIndex":0},
{"key":"auth_username","value":"wialon","enabled":true,"sessionValue":"wialon","sessionIndex":1},
{"key":"auth_password","value":"abc123!","enabled":true,"sessionValue":"abc123","sessionIndex":2},
{"key":"auth_token_duration","value":"2592000","enabled":true,"sessionValue":"2592000","sessionIndex":3},
{"key":"auth_client_id","value":"wialon","enabled":true,"sessionValue":"wialon","sessionIndex":4},
{"key":"auth_redirect_uri","value":"login.html","enabled":true,"sessionValue":"login.html","sessionIndex":5},
{"key":"auth_response_type","value":"token","enabled":true,"sessionValue":"token","sessionIndex":6},
{"key":"auth_access_type","value":"0x200","enabled":true,"sessionValue":"0x200","sessionIndex":7},
{"key":"auth_activation_time","value":"0","enabled":true,"sessionValue":"0","sessionIndex":8},
{"key":"auth_flags","value":"0x2","enabled":true,"sessionValue":"0x2","sessionIndex":9}]
I've then added a collection which currently has one action Get - Login. This action is pointing at the Environment created earlier. I can see it in the left of the document bar. The URL is as follows:
http://{{hostname}}/login.html?client_id={{auth_client_id}}&access_type={{auth_access_type}}&activation_time={{auth_activation_time}}&duration={{auth_token_duration}}&lang=en&flags={{auth_flags}}&user={{auth_username}}&redirect_uri={{auth_redirect_uri}}&response_type={{auth_response_type}}&css_url
The first error I get, and the most confusing for a new user is
GET https://undefined/get?client_id=undefined&access_type=0x200&activation_time=0&duration=undefined&lang=en&flags=0x1&user=wialon&redirect_uri=login.html&response_type=token
Error: DNSLookup: ENOTFOUND undefined
Most of the variables are undefined. This causes the DNS error, but there's no explanation of why they are not defined. They're clearly set in the environment pane and when hovering over in the action parameters.
The second error, and probably related is:
JSONError: Unexpected token u in JSON at position 0
Error: DNSLookup: ENOTFOUND undefined
This is probably due to the word undefined starting with a 'u'
Why are my variables undefined? How do I fix it?
edit: Requested screenshots
Action page
Environment Page
Post run errors
Edit: Additional testing
I cloned the action and removed all variable references, hardcoding values in the properties page. Running this gave back the same undefined errors.
After that I tried copying the URL and placing it in the browser address bar. This worked. There was a manual prompt to enter a password, but the url after that returned the access_token as described. Here is the API ref