End gateway not generated after killing Ender Dragon on Realm Server

Yesterday, I was the first person to kill the Ender Dragon on my Realm. Today, I wanted to explore the end some more and get Shulker Boxes/Elytra.

Reading the wiki on End Gateways I saw the 20 points they should spawn at. So I created a ring around the island going to each of those points and didn't find a single one.

I've downloaded the world from my Realm and will attach the level.dat file for it