Hello @tiocalibe
welcome to the SonarSource community!
If I understand your report, the Reference Branch new code period is not working for projects hosted in a TFVC repository and SonarQube equipped with the scm-tfvc plugin?
The scm-tfvc plugin is not something SonarSource maintains or supports, but I’ve made a quick check in its code and it appears that it does not implement the forkDate() method that was added to the ScmProvider abstract class for the reference branch New Code period implementation in version 8.4. Here is the TfsScmProvider.java implementation.
You may want to reach out to the lg2de / sonar-scm-tfvc project team directly about this.
Best regards
Sylvain