Gen 4/Diamond - Injected wondercards do not activate gift flag

[glencoe2004]

Describe the bug
In Pokemon Diamond (and possibly other Gen 4 games, I haven't tried them yet), PKHeX does not set a "Gift Active" flag when injecting wondercards, thus causing injected wondercards to not be collectable from the deliveryman.

To Reproduce
Steps to reproduce the behavior:

1. Open a Diamond savefile in PKHeX
2. Inject wondercard
3. Go to pokemart and observe that there is no delivery man

Also, I've found a program that seems to be able to set the flag: https://projectpokemon.org/home/forums/topic/5870-pok%C3%A9mon-mystery-gift-editor-v143-now-with-bw-support/page/12/#comment-99506

To use it, load the save file, then on the left side of the program click on the "Gift Active (D/P only)" checkbox

I've attached two saves, one from before "treatment" and one after, to help in debugging:
Saves.zip

Expected behavior
The flag should be set correctly, so the gift can be received from the deliveryman

Screenshots
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Additional context
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