I have sent you an email with a debug version of WinSCP to address you have used to register on this forum.
I was not able to reproduce the problem. Please attach the logs as per my previous post.
Please attach a full log session and debug log files showing the problem (using the latest version of WinSCP).
If to use a mask for files in session.PutFiles, in FileTransferProgressEventArgs Properties FileName returns the catalog instead of a name of transferred files. How to receive in that case a name of files?