A quick question for you, which workflow are you following to generate the Auth Token for your user? Did you first retrieve their API Key then generate the User Authentication Token? Which API are you calling caused this 405 error? Normally, it’s because of the wrong REST method you used, etc, POST vs PUT/GET, so please make sure you are using the correct API.
I checked all of the calls and yes, I was doing a POST call on the last one. After coming back from lunch, I ran the same calls again and this time they worked. Not sure what that is about but it is now functioning as expected!