(also sent via email:)
Sorry about the inconvenience, this is categorized as a bug that I would like to have fixed in an update. When copying over an element, there are many action attributes that wouldn’t be able to apply to the other scene… yet there’s some (like go to URL) that would and those should be preserved but aren’t right now.
A workaround would be to put your symbol/element temporarily within another symbol. If you copy that symbol to the new document, it you could then copy/paste with animations out and it would preserve the actions. (Make sure to Undo in the original document). That’s the best workaround we have now, but clearly not ideal.