I have WinSCP version 126.96.36.199 sitting on a Windows 2016 Server.
By means of a batch file I call this to SFTP files.
It used to transfer multiple files fine, but now it seems to only do one at time.
I saw a topic about timestamps, and have the following command in the batch file which is unchanged since day one:
"put *.* -nopreservetime -nopermissions"