Enlightened Data Transport Not working with Double Hop DMZ scenario

EDT requires policy on the XenDesktop to be enabled and DTLS on the NetScaler to be ON. Also, StoreFront needs to be minimum Version 3.8 and Citrix Receiver at 14.7. So all the requirements are met. At theXenDesktop Policy for "HDX Adaptive Transport" is set to "preferred", still connections fail...