This situation occurs when you set Take Profit or Stop Loss using the "Amount" option instead of "Price". In this mode, the terminal automatically calculates the price level at which the trade's result will match the specified profit or loss in USD.
Since the final trade result takes into account commissions and potential changes to the opening price (e.g., due to weighted average entry prices), the target closing price will be adjusted dynamically to ensure it aligns with the dollar value you entered for Take Profit or Stop Loss.