btw, while I still don't know the exact layout of your document, but if there is only one checkbox CC associated with each property value then you are spinning a lot of wheels looping through CCs:

Sub CheckBoxesByTag()
    Dim lngProp As Long
    Dim arrProperties() As String
    Dim varValue As Variant
    Dim oCC As ContentControl
    'Define the names of the custom properties to check
    arrProperties = Split("DCR Type|Classification", "|")
    'Loop through each property name in the array
    For lngProp = 0 To UBound(arrProperties)
         'Get the value of the custom property
        varValue = ActiveDocument.CustomDocumentProperties(arrProperties(lngProp)).Value
        If Not IsEmpty(varValue) Then
            'Get the specific oCC associated with that value e.g., tag = value
            Set oCC = ActiveDocument.SelectContentControlsByTag(varValue).Item(1)
            oCC.LockContents = False
            oCC.Checked = True
            oCC.LockContents = True
        End If
    Next lngProp
   lbl_Exit:
  Exit Sub
End Sub