Hi again Blandine,
Yes, this is again normal

tests are linked to requirements only through specifications.
To sum up:
Requirements <-----> Specifications <------> Tests
If I added a direct link between requirements and tests it would expose the system to a huge list of inconsistencies and/or different ways to compute the coverage. I did try one time but it was really a nightmare so at the end it did not really make sense to me.
The questions that sometimes people are then asking is "if I don't use specifications but only requirements how do I do to get coverage metrics?" my answer to this question is then "it's not ideal but use the specification tab to handle your requirements or... change your process the righ way by using requirements AND specifications

".