I've been through every post I can find on this and still no luck. I've got code for authorizing with and connecting to the REST API. In a test environment running 22.214.171.124 this all works flawlessly, in production running 126.96.36.199 it's always getting a 403.
What I've Tried
I've been over the configuration multiple times, the roles and permissions are configured correctly, everything is the same, yet it always fails in production.
The company maintaining the server are sure the request is being handled by Magento, and one curious thing I have noticed is that if I omit part of the authorization header in test it'll tell me:
In production the only response I ever get back when hitting a valid URL is:
The only other difference is that production forces HTTPS, while in the test environment there's no valid cert and so I have to use HTTP.