(previously thought) legit Pokémon with invalid HT memory and Language

[DoughnutKing]

It's on a few Pokémon I thought were legit that I transferred in from Pokémon Home into Shining Pearl.
Any idea if this is a glitch with the software, or if these mon were modified, which settings would this effect.

[Atrius97]

This is a known issue, Pokémon that arrive via Pokémon Transporter may have no HT language and a strange HT memory.

This CAN happen legitimately, but currently PKHeX doesn't validate it, and it's a temporary issue anyway, as all HT values are rewritten any time the Pokémon is traded or transferred to a new savefile. You're safe to ignore the error, it will resolve on its own as you move the Pokémon between games.