"The source path must be contained in the project root folder"

I'm new to VS Code and now trying to convert an Eclipse project to VS Code.
I have multiple Java projects stored in a common folder.
Each project have its own .vscode/settings.json file.
The projects refer to each other on source level as which requires cross-project references.
The projects are unmanaged using VS Code terminology.

Environment

• Operating System: Mac Sonoma 14.4.1
• JDK version: 21
• Visual Studio Code version: 1.88.1
• Java extension version: 1.29

Steps To Reproduce

1. Try to add a source path from another project in the folder.
   Then you get the error message from the issue.

[Please attach a sample project reproducing the error]
Please attach logs

Current Result

Expected Result

Additional Informations

If this will be addressed, I think "sourcePaths" should permit relative and absolute paths to any folder.

Commencez par reproduire l’erreur avec plusieurs projets Java et leurs fichiers .vscode/settings.json. Examinez comment le paramètre sourcePaths est validé lorsqu’il fait référence à un dossier situé en dehors de la racine du projet. Le travail est terminé lorsque le chemin source interprojets prévu est accepté et qu’une couverture de régression existe pour la configuration signalée.