[Animation Editor] Import and Export makes hitboxes on legacy files not work

[LittlePlanetCD]

Before opening this issue, I ensure that...

• I have checked both open and closed issues and confirmed this bug has not already been reported.
• I am not asking for tech support (e.g. error when starting program or trying to build).
• I am not reporting an issue with assets/scripts/logic of a specific game/mod; this bug is directly related to the editor itself.
• This bug is not related to any unofficial forks of the editor, and any issues with those should be kept in the appropriate repository.

Editor Tool

Animation Editor

RSDK Version

v4, v3, v2, v1

Expected Behavior

import and export work fine without breaking

Actual Behavior

hitboxes dont import

Steps to Reproduce

1. load a legacy animation file, like S1 Sonic
2. Export whole animation file
3. import it over or as a new animation file
4. see that there's no hitbox data

Screenshots

No response

Was another editor used on the file(s)?

No.

Platform

Windows 11 23H2

Additional Comments

i also noticed that it makes the sprites stop rendering if you import the json over an existing anim file. this could be intentional afaik but that hitbox stuff is definitely not.

exporting individual animations and importing them doesnt break the sprite renders or hitboxes of any animation, including the one that was just imported

v5 anim export and import don't have issues with hitboxes, those work as intended.