long story short, when I do this:

 setup(props) {
       console.log(props.orders[0].order_line[0].reserved);
       let myOrders = props.orders.map((el) => el);
       myOrders[0].order_line[0].reserved = false; 
       console.log(props.orders[0].order_line[0].reserved,myOrders[0].order_line[0].reserved)
 }

I got this:

true
false false

Maybe I'm missing something basic but I even tried with the spread operator or Object.assign and still got the same result! Does someone knows what it can be?