(How) can I use the [Range] attribute on a [Serializable] class?

[YoloJero]

I have a class

public class Example : MonoBehavior {

    [Serializable]
    public class SubExample {
        [SerializeField]
        [Range(1,6)]
        private int _Count;
    }

    [SerializeField]
    private List<SubExample> _exampleList;

    [SerializeField]
    [Range(1,6)]
    private int _testRange;
}

In the inspector anyway only the _testRange is displayed as Range while the _Count of the elements of _exampleList are only shown as number.

Am I missing something to get the Range behavior also on the variables in serializable elements of the list?

[TSI25]

It works just fine for me. What version of unity are you in? do you have any compilation errors? did the script get saved before you let it recompile?