Schema validation error when trying to forward email using EWS CreateItem operation

I am getting the below error when I try to forward an email using EWS create operation.

The request failed schema validation: The element 'ForwardItem' in namespace 'http://schemas.microsoft.com/exchange/services/2006/types' has invalid child element 'Subject' in namespace 'http://schemas.microsoft.com/exchange/services/2006/types'. List of possible elements expected: 'CcRecipients, BccRecipients, IsReadReceiptRequested, IsDeliveryReceiptRequested, From, ReferenceItemId, NewBodyContent' in namespace 'http://schemas.microsoft.com/exchange/services/2006/types'

As per this link 'Subject' is a valid element under 'ForwardItem'. I am using Exchange2013. Any thoughts on what I am doing wrong? The same request works with O365.

SOAP Request

<?xml version="1.0" encoding="utf-8"?><soap:Envelope 
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"              
 xmlns:m="http://schemas.microsoft.com/exchange/services/2006/messages"               
 xmlns:xsd="http://www.w3.org/2001/XMLSchema"              
 xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"               
 xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types"> 
<soap:Header>  
 <RequestServerVersion Version="Exchange2013" 
 xmlns="http://schemas.microsoft.com/exchange/services/2006/types"
 soap:mustUnderstand="0" /> 
</soap:Header>
<soap:Body>  
  <m:CreateItem MessageDisposition="SendAndSaveCopy"> 
  <m:Items> 
  <t:ForwardItem>
  <t:ToRecipients>
  <t:Mailbox>                               
   <t:EmailAddress>admin@test.onmicrosoft.com</t:EmailAddress>
  </t:Mailbox>
  </t:ToRecipients>         
  <t:Subject>Email Submitted</t:Subject>   
  <t:ReferenceItemId Id="AQMkADJmMTI3Njk1LWZjOWItNDM2Os.."
   ChangeKey="CQAAABYAAAAmV1x/D6z5Q7lUEv1+KENlAAAAAACV"/>          
  <t:NewBodyContent BodyType="Text"></t:NewBodyContent>     
 </t:ForwardItem> 
 </m:Items> 
</m:CreateItem>
</soap:Body>
</soap:Envelope>

ForwardItem requires elements to be in the order they are defined in the schema - ForwardItem

Try moving the Subject above ToRecipients:

<t:ForwardItem>
<t:Subject>Email Submitted</t:Subject> 
<t:ToRecipients>
<t:Mailbox>                               
 <t:EmailAddress>admin@test.onmicrosoft.com</t:EmailAddress>
</t:Mailbox>
</t:ToRecipients>           
<t:ReferenceItemId Id="AQMkADJmMTI3Njk1LWZjOWItNDM2Os.."
 ChangeKey="CQAAABYAAAAmV1x/D6z5Q7lUEv1+KENlAAAAAACV"/>          
<t:NewBodyContent BodyType="Text"></t:NewBodyContent>