Problems disappear temporarily when file is closed and reportingScope is set to workspace

I think this might be controlled by VS Code but filing it here just in case.

When "mypy-type-checker.reportingScope" is set to "workspace" and you have multiple files with problems reported by mypy, closing the files will make them disappear from the problems window temporarily. Once you open another file, it shows back up.

https://github.com/microsoft/vscode-mypy/assets/45497113/a3323846-d698-4895-b057-469a48bb2d01

Start by reproducing the report with mypy-type-checker.reportingScope set to workspace, multiple files with mypy problems, and the files closed. Check whether reopening another file restores the Problems view and determine whether the behavior belongs to vscode or this extension; done means the problems remain visible or ownership is established.

Written by the indexing model from the issue text.