It is necessary to take into consideration that the price consists of two components – Bid price and Ask price.
Bid price is displayed on the chart.
Sell order is opened at Bid price and closed at Ask price.
Buy order is opened at Ask price and closed at Bid price.
The take profit level of your Sell order is 1.3121. The price on the chart reached 1.3120, but the order did not close at the take profit point.
The chart shows the Bid price, while the sell order is closed at the Ask price (Ask=Bid+spread) with Bid=1.3120 and Ask = 1.3123. So, your order was not closed due to its minimum price equalling 1.3123.