Does your password have any special characters?

See also https://winscp.net/eng/docs/troubleshooting#scripting

If it does not help, please post a full session log file both from SSIS and a manual execution of your script.

So I can use the UI to log on just fine. I can also utilize the WinSCP.com to logon just fine.
I have a WinSCP Script in my SSIS Package and my WinSCP Execute Process Task with the following line...
open sftp://User name:Password@Server Name -hostkey="ssh-rsa 1024Host Key Cryptique

When we look at the log file we see...

. 2020-03-23 13:33:54.053 Looking up host "Host Name" for SSH connection
. 2020-03-23 13:33:54.176 Connecting to IP Address port 22
. 2020-03-23 13:33:54.263 We claim version: SSH-2.0-WinSCP_release_5.15.9
. 2020-03-23 13:33:54.335 Server version: SSH-2.0-WS_FTP-SSH_8.6.0.1027
. 2020-03-23 13:33:54.375 Using SSH protocol version 2
. 2020-03-23 13:33:54.411 Have a known host key of type rsa2
. 2020-03-23 13:33:54.446 Doing Diffie-Hellman group exchange
. 2020-03-23 13:33:54.577 Doing Diffie-Hellman key exchange with hash SHA-256
. 2020-03-23 13:33:54.894 Server also has ssh-dss host key, but we don't know it
. 2020-03-23 13:33:54.929 Host key fingerprint is:
. 2020-03-23 13:33:54.966 ssh-rsa 1024 Host Key Cryptique
. 2020-03-23 13:33:55.012 Host key matches cached key
. 2020-03-23 13:33:55.051 Initialised AES-256 SDCTR client->server encryption
. 2020-03-23 13:33:55.114 Initialised HMAC-SHA-256 client->server MAC algorithm
. 2020-03-23 13:33:55.166 Initialised AES-256 SDCTR server->client encryption
. 2020-03-23 13:33:55.211 Initialised HMAC-SHA-256 server->client MAC algorithm
! 2020-03-23 13:33:55.310 Using username "Username".
. 2020-03-23 13:33:55.446 Server offered these authentication methods: publickey,password
. 2020-03-23 13:33:55.482 Prompt (password, "SSH password", <no instructions>, "&Password: ")
. 2020-03-23 13:33:55.523 Using stored password.
. 2020-03-23 13:33:55.563 Sent password
. 2020-03-23 13:33:55.647 Password authentication failed
! 2020-03-23 13:33:55.687 Access denied
. 2020-03-23 13:33:55.740 Server offered these authentication methods: publickey,password
. 2020-03-23 13:33:55.844 Prompt (password, "SSH password", <no instructions>, "&Password: ")
. 2020-03-23 13:33:55.914 Disconnected: Unable to authenticate

A little miffed by...
. 2020-03-23 13:33:55.446 Server offered these authentication methods: publickey,password
. 2020-03-23 13:33:55.482 Prompt (password, "SSH password", <no instructions>, "&Password: ")

Are we missing something in our scripting?

Thanks for your review and am hopeful for a reply.