Root page is overwritten

When I start the import by adding `?sheet=BatchImport.BatchImportSheet` to the URL of the root page where I want to import my pages, I get the import wizard. After the import is finished, the root page is changed. Whenever I return to the root page, I get the start page of the wizard, instead of the original root page. Luckily, I can revert this using the page history. But it would be better if the wizard only appears when I (re-)add the `?sheet=` request parameter.