I transfer files using FTP without encryption.
I use the commander GUI.
I connect to a server at OVH.
You can see the session log at https://pastebin.com/9iDKZMmF.
I do a lot of updates, copying local files to the remote server.
When I copy a complete directory, WinSCP always copies certain files, even when I indicated to only copy new or updated files and I just copied them.
The strange thing is that, when I go into the directory, I select the files separately and copy again, those files are not recopied.
I tried this both in automatic and binary transfer mode.