I was constantly seeing this error:

Permission denied.
Error code: 3
Error message from server: Permission denied

In my case there was a difference with the timestamp. Fixed setting this:

If that doesnt work, try the following:

https://ntalam.com/2022/01/15/winscp-writing-permissions-using-debian-10/
https://ntalam.com/2023/03/15/winscp-error-2/