Make a GIF animation, export each frame, import it to C2, set the poligons of collision to be the same for all animations. If it not solve your problem, you'll need to edit your project file, so, save it in folder, open your notepad, search where have the collision boxes and replace all of them on the designated object (player, for example) to be the same.
After this, you may happen to have the bug about the collision box getting the old frame size (that size of the very first empty frame, happen when you create a new object sprite and not import a image from your explorer, for example). To solve it, you can wait Ashley, or, edit the game files where have the image sizes written, replace them with the right sizes.