Thanks. I do not see any settings difference in the logs anymore. Though when I try to connect using WinSCP 6.1 to your server's IP, I have no problems. Don't you have some application-level local firewall rules in place, that might allow WinSCP 5.17, but block WinSCP 6.1?

Sorry, meant to add those. Here are the logs.

Ok, so please post logs that show that.

I've matched Both Version's setting exactly however V6.1 does not prompt for a password when 5.17.10 does. It almost appears that the Username isn't sent.

In WinSCP 6.1, you have limited TLS version to 1.2 for some reason:

. 2023-06-01 08:13:07.950 TLS/SSL versions: TLSv1.0-TLSv1.2

And your servers seems to require TLS 1.3. So your problem is not about any prompts.
If you keep the default settings (with TLS up to 1.3), the connection should succeed.
https://winscp.net/eng/docs/ui_login_tls

Here are my logs from both Versions of WinSCP. V5.17.10 & v6.1.

Thanks for your report. Can you please post session log files from both versions?

When establishing a connection to an FTP server, WinSCP prompts for Username but does not prompt for Password, resulting in a "Connection failed" error message. This occurs on the latest version (6.1 Build 13674 2023-05-23) of WinSCP, however on an older version (5.17.10 Build 11087), it works as expected.