namespace not getting generated in transformed XSL

Oracle 12C system does not transform the XML with required namespaces.

namespace is declared in xsl transformation, while testing in Jdeveloper 12c the namespaces are generating as expected. but in server it is not generating, and the same code is working as expected in test Environment and other higher Environments.

Expectation:

<despatch_advice:despatchAdviceMessage 

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 

xsi:schemaLocation="urn:gs1:ecom:despatch_advice:xsd:3 ../Schemas/gs1/ecom/DespatchAdvice.xsd" 

xmlns:despatch_advice="urn:gs1:ecom:despatch_advice:xsd:3">

.....

</despatch_advice:despatchAdviceMessage>

Actual:

<despatchAdviceMessage 

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 

xsi:schemaLocation="urn:gs1:ecom:despatch_advice:xsd:3 ../Schemas/gs1/ecom/DespatchAdvice.xsd"