.NET FHIR Error with "initial" in Questionnaire

I’m having issues validating Questionnaires where an initial value is used. I believe i’m following the standard such as the type being same as initial. Is this a known issue or is there something i’m missing

Here is the error received and message snippet below

Encountered polymorph member initial, but is does not specify the type used (at Questionnaire.item[2].item[2].initial[0])

Thanks

			{
				"linkId": "1163",
				"text": "Check Box 2",
				"type": "boolean",
				"required": false,
				"repeats": false,
				"readOnly": true,
				"maxLength": 1,
				**"initial": [**

** {**
** “valueBoolean”: false**
** }**
]
},