(and possibly earlier versions)
In 3.13, when I upload files via FTP, the new files do not appear in the list output from ‘/file print’, or in winbox. This happens with new files. If I overwrite an existing file the old file information (size, time stamp) remains (in my case, the old file was 950B, new file is 404B). But, if I do a listing in FTP, things look as they should.