Hello! Adding my contribution here with some Pokémons that are legal (Scarlet save just extracted and loaded for the first time) but recognized as illegal.
I think there is two met location issues, one moveset issue, and two marking issues. Good luck!
EDIT: I'm using PKHeX (20221124)
637 - Pyrax - B4A17620356D.pk9 735 - Argouste - 8DD30DC1C6F1.pk9 861 - Angoliath - 957203B5FE4B.pk9 919 - Filentrappe - 562AD9C1309A.pk9