Mongoose finds empty array when it shouldn't

I am trying to find a SoldProduct with intimeOrderNumber equal to '3'.

var query = { intimeOrderNumber: '3' };

But I get an empty array.

SoldProduct.find(query, function(err, soldProducts) {
  if (err) {
    console.log(err);
  } else {
    console.log(soldProducts.length);
    for (var i = 0; i < soldProducts.length; i++) {
      if (soldProducts[i].intimeOrderNumber === '3') {
        console.log(typeof soldProducts[i].intimeOrderNumber);
        console.log(soldProducts[i].intimeOrderNumber);
      }
    }
  }
});

Output:

0

But when I change the query like this:

var query = {};

and run the same find, it's evident that there actually is a SoldProduct with intimeOrderNumber equal to '3' in the database because the output changes to:

15
string
3

I have intimeOrderNumber: String in the SoldProduct model definition. Why does the first query return an empty array?