Using perl LWP-UserAgent results in 401 Unauthorized

I'm working on a perl backend API client to interact with the RHEV API and had this working in 3.0, however when trying to use LWP UserAgent against the 3.1 API I get a 401 Unauthorized error. Using the same credentials with Curl works. Were there any changes in 3.1 that would affect how an API call method would change?