Test Steps modifying properties cannot be used twice

Hello,

I created a test case using the test step "Data Gen" to generate a unique string and test step transfer to transfer the generated value to a test case property.
This combination will be used in a data loop together with several SOA messages.
When ending the data loop the test case shall generate a different unique string but use the same test case property.
Obviousely the first "Data Gen" test step uses the same script as defined in the second "Data Gen" test step but not the script defined in itself.

The structure of the test case looks like this:
- Data source
- Data Gen
- Transfer Properties
- SOA request
- Data loop
- Data Gen
- Transfer Properties
- SOA request

Why does the the first test step "Data Gen" use the function defined in the second one even if the name of the functions are different?

Greetings
Andi