Sonar scan fails with Module A is already part of project B

We have a multi-module project with the deployment pipeline auto-wired to Sonar Version: ‘6.7’

Scan fails with: Module A is already part of project B

I came across https://stackoverflow.com/questions/25500925/sonar-module-is-already-part-of-project-or-how-to-upload-projects-with-same-d

BUT when trying to implement this, our intellij editor chokes on adding the following line:

<sonar.moduleKey>test</sonar.moduleKey>

(points out a syntax error)…
Thoughts ? Thanks.

Hi,
What error do you get exactly? Other than the syntax error given by IntelliJ, is the scan now working?