When you open a project with external links (e.g.: external task dependencies, subprojects) from Clarity to Microsoft Project, the referenced projects are also opened as projects in MSP.
Any supported Clarity version.
This is working as designed.
When you open a project, the MSP integration will open its project dependencies as well.
For example, if you have the following scenario:
When you open 'Main Project' using the MSP integration, you should see three different project windows: 'Main Project', 'Some Other Project', 'Subproject 1'.