My Minecraft world was started in Pre-Release 20w18a were there was a bug that stoped end gateways from spawning. Since the update to 20w20a were the bug was fixed I have defeated the ender dragon 15 times and no gateways have spawned. I have done everything I can think of but they don't spawn. I have reset the end and also optimized the world and killed the ender dragon after both times.