Steps to reproduce the issue

Change both path's of the Media Manager configration, i.e. 'Path to Files Folder' and 'Path to Images Folder'.

Open Media Manager.

Expected result

A list of files in folder 'Path to Files Folder', if there are any, or an empty folder otherwise.

Actual result

The result depends on proper configuration of the FileSystem - Local plugin. If no directory is chosen, which is the default, the plugin returns [{"directory": "images"}] and the Media Manager shows nothing.

System information (as much as possible)

A fresh Joomla! 4.0 installation, or at least with unaltered FileSystem - Local plugin configuration.

Additional comments

My suggestion is to return Media Manager's 'Path to Files Folder' setting from FileSystem - Local as a default and not [{"directory": "images"}].