PUT REST method not working behind reverse proxy

We have a website that is running through reverse proxy. Out site uses REST web services which work fine when the site is accessed directly. But when the site is accessed via the reverse proxy address the PUT REST method returns a 503 error and PUT requests do not appear in our server logs. GET and POST requests work as expected and do appear in the server logs. Are PUT REST methods supported by reverse proxy? UPDATE: We have spoken to a contact in the reverse proxy team who suspects the AAA Access Manager is rejecting the PUT requests. We have reached out to some people in the AAA team to confirm that all HTTP Verbs are enabled on the AAA Admin CPAC servers' PA profile. Will update this question as the story unfolds.