The SonarQube docs specify:
When analysis is triggered from a Pull Request the SonarQube Scanner for MSBuild - End Analysis task decorates the updated source code in the Pull Request with the new code quality issues, instead of pushing the analysis report to the SonarQube server.
How can you turn this on? We are using TFS 2018 with version 3.x of the SonarQube TFS/VSTS extension.