End Gateway Portals not teleporting player to the end islands.

After defeating the Ender Dragon, a End Gateway Portal appears as expected, however, when an enderpearl is thrown into it, the player is just teleported to the starting platform of obsidian on the original enderdragon platform. This was tried multiple times with the same portal, and then defeated the enderdragon twice more to spawn 2 new portals, both with the same effect as the first gateway portal. Building out to the ender islands instead of teleporting via an end gateway portal shows that there are no end cities/ships, making the elytra and much other loot unaccessable.