Origin Seed marked with (X)

[lantern]

I'm trying to make a legal Naive Raichu with perfect IVs encountered in LeafGreen.

Using the IVs to PID tab in PokéFinder, I found this Seed + PID + SID combo:

Entering this in PKHeX renders the Pokémon legal, but the Origin Seed is marked as "(X)".

Does this mean the Pokémon is technically not legal? And if so, why does it not align with the data from PokéFinder? How should I go about finding a "fully legal" spread?

Thanks to anyone helping out in advance!

[Kaphotics]

Wild Pokémon are not simply Method 2; they result from the Wild 1/2/4 methods.

The program is unable to find an encounter frame where you acquire said Raichu. Pokéfinder won't show you a frame either, because none exist for that spread/slot.

[lantern]

Ahh that makes sense! Thanks for the explanation, much appreciated!