Portals don't link correctly.

Expected behavior

• Linking nether portals in 3D (x,y,z) for a chunk loader array in 3x3 grid. Meaning 2 chunks on overworld between the chunk the portals are in.

• Inside 128 block range -> Portals should link to the closest portal depending on coords.

• For chunk loaders that means Portal A drops players and items in Portal A nether side. Portal B on B nether side and so on.

• Tested and confirmed in vanilla.

Observed/Actual behavior

Portals do link, but will sometimes forget what portal they linked to and prioritize a different one that is not alinged to it.

Steps/models to reproduce

1. Test wdl 1 in vanilla with player and also throw items (place a few blocks to catch a thrown item since portal hovers over lava).

2. Check F3 + G for mentioned chunk spacing (2 chunks).

3. Test red to red, vice versa. Blue to blue, vice versa. Red to nether blue, vice versa. Blue to nether red, vice versa.

4. Works perfectly.

5. Copy world to plain 1.21.7 Build # 32 server and redo it several times the same way. It will break. Player and items will arrive in the wrong portal.

6. Test in vanilla and on paper with attached chunk loader (litematica schematic) or use provided wdl 2 with already set up chunk loader.

7. [Paste clocked sender side (overworld) aligned west with 4 items in the hopper clock and 1 item in the dropper.

8. Paste self-clocked recierver side (nether) aligned east with 1 item in the dropper

9. Remove signs inside the portal and press the lever on sender.]

Conclusion: Running only one chunk loader sometimes works fine, running 2 loaders, one from red to red and one blue to blue portal will break it every single time, even when items shoot unsynced. -> Bug, should not happen

Plugin and Datapack List

None and standard paper config.

Paper version

1.21.7 Build # 32

Other

Wdl 1:
Portal Test.zip

Chunk Loader schematic:
Chunk Loader.zip

Wdl 2:
Portal Test with chunk loader.zip

Start by reproducing the issue on Paper 1.21.7 Build #32 with Wdl 2, the supplied chunk-loader schematic, and the two portal loaders, then compare the same setup in vanilla. Trace the portal-linking behavior involved in selecting destinations. Done means both loaders consistently send players and items to their aligned portals, as in vanilla.