WinSCP 6.3.1.Unable to get a connection to SFTP via proxy – FileZilla works (inside aws)

I use WinSCP for several years but this time I am not able to get it working. The needed server changed from FTP to SFTP with key. I got it working locally! But in the cloud there must be a mistake. FileZilla got it but I want to keep using WinSCP. Maybe any ideas? I tried with proxy and using SSH tunnel. I think the logs would show better what I did :-)

Thanks for your report.
Can you please try the same using WinSCP 6.1.2 and 5.21.7?
https://sourceforge.net/projects/winscp/files/WinSCP/

I tried with both. Unfortunately not working. I posted the logs. Thanks for your help!

Thanks! Ok and what about 5.19.6?