I killed the ender dragon in 1.18.2 and the end gateway didn't spawn anywhere. I searched all around the island but there is no way to find it. The only thing I can think of is that the world is an old backup of 1.17.1.
In the attachments I uploaded the End folder DIM1 in .rar format
How to reproduce it:
Enter the end
Destroy all the cristals
Kill the ender dragon with beds, arrows and an enchanted diamond sword, the final shots are made using only the sword
Gain all the exp and exit end
Re-enter the End to look for the end gate
World seed: 6309057395054918058 (stronghold at 1365 -432)
Day 723
Mojang can't fix this bug if you don't tell them how to reproduce this bug. This sounds more like an user mistake than an actual bug.