...

Have you created a different issue type to use it as a Requirement, but you can not see why it is not taking this behavior?

Correct 

Image RemovedImage Added

Not correct

Image RemovedImage Added

Solution

You need to configure your issue type as a Requirement in the Xray settings:

1 - Go to Jira Administration

2 - Go to Add-onsManage apps

3 - Go to Xray

4 - Go to Issue Type Mapping

Image RemovedImage Added

5 - Drag and drop your issue type from the "Available Issue Types" box to the "Requirement Issue Types" box

Image RemovedImage Added

6 - Save

Link for related documentation

...