Hi. I’m facing a very similar problem. I’d like to know if you have any new information.
Some issues are being detected as “new code” on several different projects. Although Sonar detects it “2 days ago”, the last changes in these classes are more than 4 years old.
I’m using Version 8.9.6 (build 50800). We’ve began noticing the problem after implementing the workaround described in False positive on S1206 - #6 by michele.lorenzini (SONARJAVA-4023). We’re not sure if this issue is solved on version 8.9.7. However, we are not sure that the new code problem is related with the workaround (add a path to vm.jar on sonar.java.libraries), since the problem still exists after undoing it.