Teleporting through an End Gateway teleports you through, but instead of falling onto the island below, it pushes you off the edge and you are unable to do anything. I've tried placing blocks and water but nothing worked. I eventually built a bridge out to where the portal teleported to and built a large platform underneath, but that still didn't stop it from pushing me off the platform and being pushed into the void. Very frustrating as I am unable to explore the End without crossing a 1000+ block bridge, and I lost a lot of valuable gear.