sensitive information exposure assertion fails for null/empty response

I am using the default sensitive information exposure assertion for a (Rest) GET request.

When I run the request directly in a test case (with parameters set appropriately) and get a '304' HTTP response (not modified), this assertion passes.

If I repeat this test by running via a modularised 'run test case' to replicate this, I get an error - Request - FAILED - 576
- [Sensitive Information Exposure] null/empty response. (the number varies each time).

This means that the test case in the second scenario always fails.

I am attaching a screenshot to demo