Importing Formula back in price chart


I accidentally lost my chart, with my formula which was working all fine. Now I have managed to add a chart again but when I drag the formula back to the price chart, its not the same anymore as per before. For example I delay to buy by one day, now it buys based on the signal day instead. Can you please assist me how to get my formula back on to the price chart and ensuring its working as it was. From what I have read its pretty straight forward, its just dragging the formula onto the chart and it should work - Is this correct?