JPN Duking "ギンザル" Larvitar "ヨーギラス"

[MIO1339]

There is a site called Gen 3 Ace Builder https://mankeymite.github.io/Gen3ACEPokemonBuilder/

When I check my Legal Shiny JPN Larvitar that came on XD checked by PKHeX0246 ★ - ヨーギラス - 84E9380E7C77.pk3 but while I check it on this website above shown on the photo provided is "not obtainable" even I changed the SID corresponding to PID I get even I used two PokeFinder 4.2.1 and 4.5.4 can someone explained me about this why PKHeX is legal VS. Gen 3 Ace Builder