WSO2 missing value when logging property - xpath

Question

I'm currently stuck with the following.
Goal 1: get the URL in the log
Goal 2 use it in the send mediator
Could you guys help me with both?
XML file:
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
<soap:Header>
<meta:MetaDataType xmlns:meta="http://teswt.nl/xmlschemas/meeeeta/0.1">
<meta:Version>6.3</meta:Version>
<meta:FixLevel>0.0</meta:FixLevel>
<meta:Endpoint>http://555.555.555.55:8088/sal</meta:Endpoint>
</meta:MetaDataType>
</soap:Header>
The code in the proxy insequence so far:
<property xmlns:meta="http://teswt.nl/xmlschemas/meeeeta/0.1" expression="$header//meta:MetaDataType/meta:Endpoint" name="URL" scope="default" type="STRING"/>
<log level="custom">
<property xmlns:meta="http://teswt.nl/xmlschemas/meeeeta/0.1" expression="get-property('URL')" name="URL"/>
</log>
<send>
<endpoint>
<address format="soap11" uri="http://555.555.555.55:8088/sal"/>
</endpoint>
</send>
It prints the following:
INFO {org.apache.synapse.mediators.builtin.LogMediator} - URL =

Answer 1

I have tested the given request and the XPath expression in EI 6.6.0 server and I could observe that the XPath is working as expected and logging the URL.
Request
<soap:Envelope xmlns:soap="http://www.w3.org/2003/05/soap-envelope">
<soap:Header>
<meta:MetaDataType xmlns:meta="http://teswt.nl/xmlschemas/meeeeta/0.1">
<meta:Version>6.3</meta:Version>
<meta:FixLevel>0.0</meta:FixLevel>
<meta:Endpoint>http://555.555.555.55:8088/sal</meta:Endpoint>
</meta:MetaDataType>
</soap:Header>
<soap:Body/>
</soap:Envelope>
Proxy service
<?xml version="1.0" encoding="UTF-8"?>
<proxy xmlns="http://ws.apache.org/ns/synapse"
name="test"
startOnLoad="true"
statistics="disable"
trace="disable"
transports="http,https">
<target>
<inSequence>
<property xmlns:meta="http://teswt.nl/xmlschemas/meeeeta/0.1"
expression="$header//meta:MetaDataType/meta:Endpoint"
name="URL"
scope="default"
type="STRING"/>
<log level="custom">
<property xmlns:meta="http://teswt.nl/xmlschemas/meeeeta/0.1"
expression="get-property('URL')"
name="URL"/>
</log>
</inSequence>
</target>
<description/>
</proxy>
Could you please enable the wire logs and check if the desired request is received by the service. You can also add a <log level="full"/> before extracting the URL to check the payload received.
In addition to that, what is the EI version that you are using