The Analysis Tools saves changes automatically in the browser database on each change in a field. This data is closely linked to the browser history, so clearing the browser cache/history will result in removed data.
This functionality is a comfort function and not a persistent and reliable data storage. Please create regularly backups and when you have finished your report create the report export file.
These files are saved .json files which can be loaded back in the Analysis Tools using the import function on the start page. Based on your settings in the browser you will be asked what to do with the file (save or open) or it will be automatically saved in your downloads folder.
Please do not open the file and only save it.
Please create regularly backups and report exports when you have finished them and store them on your companies servers.