Why did the Limit Order get executed immediately?

Limit Order is a type of order which allows traders to set a price called the "Order Price".

As compared to Market Orders, limit orders provide an option of traders to have better control over their position's entry or exit price at the expense of giving up order execution guarantees.

The main reasons why traders limit orders are executed immediately is due to the following:
Buy Long Order = Order Price HIGHER than Best ASK Price (Prices that traders are willing to sell)
Sell Short Order = Order Price LOWER than Best BID Price (Prices that traders are willing to buy)