I believe BE is picking up the full directory instead of one level lower which would be the specific file the user intends to be downloaded. It comes as a .zip file because of the larger amount of data (the downloader will send it to user as .zip if there is more than some cetain aount of data).
Check you SETTINGS page in BE.
In ACCESS CONTROL we have nothing checked
in UPLOAD OPTIONS we have:
Upload Options
Max upload (as defined in php.ini): 256 MB
File uploads via this plugin will be stored in the folder _bex_uploads under the Root folder. This will not be displayed via the plugin.
If you want to allow uploads into the folder that the user has navigated to, then check the Allow Uploads in Active Folder option below.
Allow uploads in Active Folder: BOX CHECKED Default is the _bex_uploads folder.)
Allow uploads to Dropbox when the WordPress user is not logged in: BOX NOT checked
Email admin on upload: BOX Checked.
Filename extensions to allow: gpx,gbd,kml,kmz
Filename extensions to exclude: (left blank)
(Note: If both 'allow' and 'exclude' are provided, the 'allow' options take priority.)
DISPLAY OPTIONS
`Display Options
By default, folders and files are shared from your Dropbox Folder/Apps/Blighty Explorer. If you want to share a subfolder under Apps/Blighty Explorer, set it here as the root folder. This allows you to share different subfolders on different WordPress installations.
Root folder: DOT / (i e filled circle)
Use “Home” as the root label or the root’s folder name: DOT Home
Show modification date: CHECKED Show size: CHECKED Show file extensions: CHECKED
Modification date format (if shown): 29 Mar 2021 10:00
Default filename sort: BOX CHECKED Ascending – Use natural sort order: NOT checked
Sort folders to top of list: Yes Checked
Download Files: CHECKED Files can either be shown in the browser (default) or selected to download.
Open Files in new Tab/Window: CHECKED Force a new tab/window to opened when a file is selected.
Select stylesheet: CHECKED Default
I hope this helps you