When you download a file (individually or by selecting several files in the same folder) this download is recorded in the activity log.
However, if you select the folder itself as the item to download, it is not recorded that the file has been downloaded (indirectly, as a result of downloading the entire folder).
Only in the project activity log (at admin level), the download of the folder is recorded (but not of the files themselves).
This is bad. When we want to audit whether a user has downloaded a particular file, the file activity log is not reliable, because the entire folder may have been downloaded, without "leaving a trace" of the download in the file.
When a user downloads an entire folder, it should be recorded in each file contained therein, which has also been downloaded.