Select the symbol in the Symbols panel... right click and select duplicate...
If you duplicate it this way you actually make a new Symbol..
If you select it in the Elements panel and the duplicate it just makes a copy of that Symbol
I'd like to add that you also need to drag the newly duplicated symbol from the symbol pane to the "Stage" and not to the "Elements" list.
This is the only way your new symbol will be added so you can begin interacting with it.
Is there any way to do this programatically via the JS api?
What version of animate are you using?