User details update should be separated into a separate thread at: https://github.com/jenkinsci/active-directory-plugin/blob/1ea9f9785a6f9e6193e62f6fe67a569a5a50092b/src/main/java/hudson/plugins/active_directory/ActiveDirectoryUnixAuthenticationProvider.java#L369

We should be returning the user details and not waiting to update... the update can take place in the background.