One of your reports was rejected or downgraded by the team leader, even though you stuck to the test description and our guidelines?
Don't get upset right away. Breathe, relax, and calm down. Read carefully the rejection reason from Team Leader, and try to understand what is the Team Lead's point of view. Sometimes tester can misunderstand the test instructions or product which is tested, or the tester can miss an already reported bug that has the same root cause or a Known Bug. In all of those cases, the bug needs to be rejected, so after the rejection, read the TL's rejection reason carefully.
If you still do not agree with the TL decision, there is a dispute feature presented for the testers, and if you want to learn more about the dispute feature, please visit the Bug Dispute Feature Academy article. But before opening any dispute, we suggest you to check the Understanding TL's Rejection Reasons Academy article.