Updating a party field clears out other party data?

Hi,

We are making a simple update to party to update an individual's email address. Our email address update goes through, but we are seeing other data cleared out/deleted at the time of the update such as Informal Name, Work Phone, Co Id,etc even though we are not making updates to those fields . Has anyone else encountered this issue?

Below is our party call.

var q = jQuery.ajax(url + "/api/Party/23280", {
type: "PUT",
headers: {
"RequestVerificationToken": document.getElementById("__RequestVerificationToken").value
},
"dataType": "json",
"contentType": "application/json",
"data": JSON.stringify({
"$type": "Asi.Soa.Membership.DataContracts.PersonData, Asi.Contracts",
"PersonName": {
"$type": "Asi.Soa.Membership.DataContracts.PersonNameData, Asi.Contracts",
"FirstName": "Quackie",
"InformalName": "",
"LastName": "Chan",
"FullName": ""
},
"PartyId": 23280,
"Id": 23280,
"Emails": {
"$type": "Asi.Soa.Membership.DataContracts.EmailDataCollection, Asi.Contracts",
"$values": [{
"$type": "Asi.Soa.Membership.DataContracts.EmailData, Asi.Contracts",
"Address": "[email protected]",
"EmailType": "_Primary",
"IsPrimary": true
}]

      }
  })

});