Azure tenant 400 bad request

[Hayden1321]

I am trying to configure Netbox to work with our new Azure SSO for our organisation however, when I try to login I get the following error:

<class 'social_core.exceptions.AuthFailed'>

Authentication failed: HTTPSConnectionPool(host='login.microsoftonline.com', port=443): Max retries exceeded with url: /837df1ed-aaaa-aaaa-aaaa-d1c9ac42fe0e/oauth2/token (Caused by ProxyError('Cannot connect to proxy.', OSError('Tunnel connection failed: 400 Bad Request')))

Python version: 3.8.10
NetBox version: 3.4.8

I have the client ID, secret, & tenant ID set in the config, for some reason I am getting this error; I have attempted to debug this a handful of ways, but I am unable to extract useful information from the error. Even with file logging enabled, I get no body response back from the request so I have no idea where to start debugging.