Not able to use custom properties in a service request

This is a very simple situation. From what I have read, it should work but it doesn't. I have two test steps. The first one is a Groovy script test step:

 

testRunner.testCase.addProperty("myProperty")
testRunner.testCase.setPropertyValue("myProperty", "12345")

 

The second step is SOAP request. In the request, I tried to use the property by ${myProperty} but it doesn't work.

 

Instead of the Groovy script, if I use a Properties teststep, it works. But I really want to use a Groovy script because I need to use more complicated logic in computing the property value.

 

Thanks for your help in advance.