I have a new installed Photoshop Elements 2020 . I can import media files to the organizer. But when I turn to a new folder and back to the earlier import folder I got the message "there are no media files. Clear the used filter and try again." When I try to import from the folder again I got the message that the files are already in the catalogue. But I can´t find the media files anywhere in the program. This happens from the beginning after new installation before I have set any filter or done anything else.
What happens if you click the left arrow to return to the grid? In All Media you have various ways of sorting your media e.g. oldest, newest etc. There is also an option to view by last import. Can you see your files in All Media rather than choosing a folder?
The filter means that either you are shown only the newly imported files just after the import, or that you have the former folder selected. If you click on the arrow 'All Media' on the left of the third line, that will clear the filter and you'll be able to select the files in another folder.