When an App Volumes agent make an HTTP request to the App Volumes Manager, NTLM is used to authenticate the user and user account with the entry in the Active Directory.
You can deactivate NTLM by defining a system environment variable on the machine where App Volumes Manager is installed.
To understand the implications of deactivating NTLM, see https://technet.microsoft.com/en-us/library/jj852241(v=ws.11).aspx.