If you copy a file using drag&drop feature or “Download a file from the server” from NoMachine tray menu – timestamps are not kept and you cannot copy folders but by using drag&drop you can copy multiple files.
If you mount disk to or from server and copy files in file browser, or by ctrl+c ctrl+v, timestamps are kept and you can copy folders. Folders do not keep timestamps, but files inside them do.
If you want to use only drag&drop or copying from server, you can pack folder into an archive and copy that archive. That way you can copy whatever you need and keep the timestamps.