Cache/minify files missing

On one website there are no files in the wp-content/cache/minify folder when checked in cpanel, but the browser inspector and source code of the page has a number of files listed, all of which can be accessed.
With other websites, similar files are visible in cpanel.
Any suggestion as what has happened to these files, I didnt think cache files were dynamically created. The W3TC settings on the two websites I am comparing are the same.
Thanks.