Presentation is not saved after duplicating other than current presentation

Tested with Windows.

Test steps:
1. Have a project with at least two presentations. Open the initial presentation
2. Add some basic objects to the scene (do not save the project/presentation)
3. Go to project palette, right-click a presentation that is not currently open and choose Duplicate presentation
4. The presentation is duplicated and the new presentation is opened
5. Go back to the initial presentation
-> The project was not saved when the presentation was duplicated and new presentation was opened. All unsaved changes are lost.