@rrivero Please review the video link and documentation below as this should provide you the steps on how to create a new user from AD. The relevant portion of the video is around the ~5:23 minute mark.
(Please visit the site to view this media)
A couple of key points I would like to kindly pass to you. The new VSA user from AD gets created automatically after the policy is modified and applied. To apply the policy in Discovery, you must click on "Apply Changes" on any of the sub-tabs within the Policy tab. If you navigate to the Domain Watch page and under the column called "User Policy Status", it should state "Applied" in the row representing your domain. If the status message is "Modified" then it's most likely the policy has not been committed by clicking on the "Apply Changes" button.
Also there is no need to go into System and create the AD user as this method only creates local VSA users. The VSA creates the AD-logonable VSA User for you to save you some extra steps. If you need further assistance, please create a support ticket on this matter and feel free to reference this post so we can assist you further.
Tim