Appending a Grease Pencil rig breaks it I have a simple 2D Rig created with Grease Pencil and deformed by weights/lattices, this is what it looks like:

But when I try to append it to another scene it looks like this:

I'm not sure why this is happening, the only way I have found to take it to another file is by importing the scene instead of the collection, this doesn't solve my problem though as the rig is in another scene
My guess is that it has to do something with strokes that are scene dependent and for some reason aren't dragged in along the rest of the rig while appending.
Does anyone have a clue why this happens?
The rig you uploaded has been drawn on frame 3, while if you append it on a new scene it's set on frame one. Even if you go to frame 1 in the rig file some strokes disappear.
To solve, you can open a grease pencil dope sheet editor and grab all strokes to frame one, or simply start animating from frame 3 and above.