Describe the bug
Gigantamax form flags aren't set on entries that otherwise have valid Gigantamax forms (Except 400 - Eternatus). If checked manually, in-game Pokédex descriptions aren't displayed, as though they haven't been captured or used. Suspect this might be what the UnknownFlag option controls.
To Reproduce
Steps to reproduce the behavior:
Expected behavior
All valid Gigantamax flags for applicable Pokémon should be enabled.
Screenshots
Current output:

Expected output:

Additional context
Valid Gigantamax Pokémon in the Pokédex:
Upon looking at an unmodified entry for Sandaconda after it was captured with Gigantamax ability, the Unknown flag was still unchecked, but the Pokédex entry for the Gigantamax data was still ???.
The flag might be set once you Gigantamax it at least once yourself.
As for the "why isn't Check All" setting Gigantamax seen flags; because some aren't released yet (Toxtricity).
That seems to be the case, using e.g. Gigantamax Eevee in a Raid Battle and Dynamaxing it is what made the Pokédex entry for it appear.
Checking against an unedited save with the latest commit, the Unknown flag is definitely what controls the full entry visibility in the Pokédex.

