Tests created under a Sub Test Execution are not shown in the Traceability Report

Tests created under a Sub Test Execution are not shown in the Traceability Report.

How to reproduce error:

1. Create an Epic (requirement)
2. Create a Sub Test Execution from the Epic (button Create new Sub Test Execution)
3. Create Test in the Sub Test Execution
4. Execute the Test
5. Check Traceability Report for the Epic created in step 1, it should have the previously created Test in the report, but it does not.