MappingJackson2XmlHttpMessageConverter creates extra/duplicate xml elements during marshalling - spring-boot

Question

i am using xjc to create jaxb binding classes from an xsd... and using MappingJackson2XmlHttpMessageConverter to convert the objects to xml.. but what i am seeing is, when i have a list in the binding file, the converter creates a duplicate xml element..
XSD:
<xs:complexType name="orderSubmitType">
<xs:all>
<xs:element name="orderId" type="xs:string" />
<xs:element name="giftCards" type="giftCards"/>
</xs:all>
</xs:complexType>
<xs:complexType name="giftCards">
<xs:sequence>
<xs:element name="giftCard" type="giftCard" minOccurs="0" maxOccurs="10"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="giftCard">
<xs:all>
<xs:element name="cardNumber" type="xs:string" />
<xs:element name="pinNumber" type="xs:string" />
</xs:all>
</xs:complexType>
JAVA:
public class TestRestTemplateConfiguration {
public static RestTemplate getTestClientRestTemplate() {
if (INSTANCE == null) {
RestTemplate restTemplate = new RestTemplate();
restTemplate.setErrorHandler(new TestClientResponseErrorHandler());
ClientHttpRequestInterceptor loggingInterceptor = new TestClientLoggingInterceptor();
restTemplate.setInterceptors(Collections.singletonList(loggingInterceptor));
restTemplate.setRequestFactory(new BufferingClientHttpRequestFactory(new SimpleClientHttpRequestFactory()));
MappingJackson2HttpMessageConverter jacksonConverter = new MappingJackson2HttpMessageConverter();
MappingJackson2XmlHttpMessageConverter jacksonXmlConverter = new MappingJackson2XmlHttpMessageConverter();
restTemplate.setMessageConverters(Arrays.asList(jacksonConverter,jacksonXmlConverter));
INSTANCE = restTemplate;
}
return INSTANCE;
}
}
final xml that is created is ..
<?xml version="1.0" encoding="UTF-8"?>
<OrderSubmitType>
<orderId>111111</orderId>
<giftCards>
<giftCard>
<giftCard>
<cardNumber>123456790</cardNumber>
<pinNumber>1111</pinNumber>
</giftCard>
</giftCard>
</giftCards>
</OrderSubmitType>
as you can see... there is a extra
<giftcard></giftcard> elements...
can anyone tell me what is the mistake that i am doing...
thanks...