When creating a Symbol with the Symbol.for method, the instance returned may be a preexisting instance. We can see this when we create a Symbol with the same string and number values. We can even see the same instance when a number is provided as a string.
When printing out the types for the keys, we can see why the numbers match, even when the argument is a string. When we retrieve a key for a numeric value, it is converted to a string, and thus is equivalent to the string representation of the number.
