Cannot configure "Project" in top right editor panel in Rider

It seems that I have two projects configured in my code editor, and the analyzer runs on the first project by default. In the top-right corner of the editor, I can see the option to switch projects:

The first project, "Documentation," is set as the default, so I need to manually switch to the second project each time to run the analyzer on the correct files.

I couldn't find any documentation about this issue in Rider.

Does anyone know how to deactivate one of the projects or set a specific one as the default?

Thanks in advance for your help!