Ender Dragon and Return Portal Don't Spawn in Brand-New World if Setting "scan-for-legacy-ender-dragon" is Set To False in paper.yml

Expected behavior

I expect the ender dragon and the (unlit) return portal to spawn upon entering the end dimension. This was observed on multiple server members' computers in Singleplayer mode.

Observed/Actual behavior

The dragon did not spawn and neither did the return portal.

This has been attempted multiple times. Results were identical for both 10 chunk and 12 chunk simulation distances.

Steps/models to reproduce

Set scan-for-legacy-ender-dragon to false in paper.yml.

In server configuration, set simulation distance to 10 or 12 (I tested both) and set render distance to 18

Enter the end through any portal (constructed or naturally generated)

The dragon does not spawn and neither does the return portal.

Plugin and Datapack List

Plugin List

BetterConcrete

CoreProtect

EssentialsX

EssentialsChat

EssentialsProtect

LuckPerms

RHLeafDecay

Datapack List

Vanilla (built-in)

file/bukkit (world)

Paper version

[01:33:26 INFO]: Checking version, please wait...
[01:33:26 INFO]: This server is running Paper version git-Paper-21 (MC: 1.18) (Implementing API version 1.18-R0.1-SNAPSHOT) (Git: a5a7782)
You are running the latest version

Other

EssentialsX and all related plugins are up to date. EssentialsProtect's option to prevent the ender dragon from spawning is disabled.

Start by reproducing the issue in a brand-new 1.18 world with scan-for-legacy-ender-dragon set to false in paper.yml, then inspect the End entry and initialization path. Done means entering the End reliably creates both the ender dragon and the unlit return portal under this setting.