@zcq0730: Yes, that's correct.

So the issue arose from our old fashion FTP server, right?
So there is no way to get the precise timestamp?
Thank you very much for your help.

It's a feature: Issue 1395 – When FTP server does not provide precise timestamp, but the timestamp otherwise matches timestamp of the last uploaded version of the file, using precise timestamp of the uploaded version instead

Please read also https://winscp.net/eng/docs/timestamp#precision

I have encountered an issue with timestamp precision. (only precise to minute level)
After uploading files into the server, I found that the timestamp seems got truncated when I logged off the session and login again. The server is running an old fashion FTP protocol.
SFTP is not supported.
Details please see the attached Log file.

Sync_List_Checked_20190408.docx [2019-04-08T10:33:35.972Z] (Original)
Sync_List_Checked_20190408.docx [2019-04-08T10:33:00.000Z] (Server Part)
In brief, the server part lost the second timestamp information. (This happens only after logoff and re-login the FTP server, since WinSCP preserves the timestamp information during a session)

Is there a way to solve this problem? Where is the problem arise from? Due to settings or it is the problem with the server?
Many thanks in advance!