Have you confirmed that this report actually shows coverage on the files you expect to see increased coverage for? SonarQube only reads the report – so if the file isn’t represented in the report or the report says there’s no coverage… SonarQube will believe it.
Yes, SonarQube reads coverage from the /tmp/jacoco.xml file only. However, when I add new test cases, SonarQube does not show the coverage. I’ve also noticed that sometimes it shows coverage for a specific file, while other times it does not.