if the image of the ‘single’ coin is really all the coins in one spot and you are taking them and stacking them up but then if you play the timeline or save and reopen the document and they go back to the ‘single coin’ then you must have set a keyframe for the coins (or maybe just the first coin but it got copied when you copied the coins). If you are not animating you won’t need the keyframe so just remove it.