On the Traceability Report, filtering by the Epic will not show the Test Set's Tests

Description
When a Sub-Requirement has Test Set linked, and the Traceability Report filter is set for the parent Requirement, the Sub-Requirement's Tests will not show.

Pre-conditions
Sub-Requirement just with Test Set linked to it:

How to reproduce

1. Have an Epic with Sub-Requirement just with Test Set linked to it:
   
   
   
2. Head into the Report and filter it by the Epic issue:
   

Actual result/Attachments
The Sub-Requirement's Tests from the Test Set will not show, while the Sub-Requirement just linked with Tests will:

Expected result
The Sub-Requirement's Tests from the Test Set show correctly, like they do when the Requirement is not a Sub-Requirement: