I currently get arbitrary results here and I don't think it is related to downloading a folder or a single file. When selecting the default (latest) file for download we always use the default GET with no version information whatsoever which should always return the latest version as with non versioned buckets. Have to investigate with AWS.
I can replicate the issue as described in the ticket.
The issue is that when download a folder all of its content including all versions are downloaded eventually overriding the locally where you will have an arbitrary version depending on what version was downloaded latest.