Populating Persistent Class from JSON

Here is my Ens.DataTransform

Class osuwmc.Epic.FHIR.DTL.FHIRResponseToPatient Extends Ens.DataTransform
{

ClassMethod Transform(source As HS.FHIRServer.Interop.Response, target As osuwmc.Epic.FHIR.DataStructures.PatientSearch.Response) As %Status
{
  Set tSC=$$$OK
  set tQuickStream = ##Class(HS.SDA3.QuickStream).%OpenId(source.QuickStreamId)
  set tRawJSON = ##Class(%Library.DynamicObject).%FromJSON(tQuickStream)
  $$$TRACE(tRawJSON.%ToJSON())
  set tResource = tRawJSON.entry.%Get(0).resource
  if tResource.resourceType '= "Patient" {
    set tSC = $$$ERROR($$$GeneralError, "FHIRResponseToPatient: Resource type is not Patient")
    return tSC
  }
  else{
    $$$LOGINFO("Resource Type: "_tResource.resourceType)
    set mrnIter = tResource.identifier.%GetIterator()
    while mrnIter.%GetNext(,.identifier) {
      if identifier.system = "urn:oid:1.2.840.114350.1.13.172.2.7.5.737384.100" {
          set target.MRN = identifier.value
      }
    }
    set NameIter = tResource.name.%GetIterator()
    while NameIter.%GetNext(,.humanName) {
      if humanName.use = "official" {
        set target.LastName = humanName.family
        set target.FirstName = humanName.given.%Get(0)
      }
    }
    set target.DOB = tResource.birthDate
    set target.Gender = tResource.gender
    set addrIter = tResource.address.%GetIterator()
    while addrIter.%GetNext(,.address) {
      if address.use = "home" {
     set target.Address = address.line.%Get(0)
        set target.City = address.city
        set target.State = address.state
        set target.PostalCode = address.postalCode
      }
    }
  }
  return tSC
}

}

If I replace the set statements with $$$LOGINFO, the values will show up in the trace viewer.