I extended it to 30 secs but that makes no difference. I have switched to Core FTP which works fine at present but I won't be surprised if it fails to connect eventually.

Does WinSCP connect if you set a longer timeout?
https://winscp.net/eng/docs/ui_login_connection
Can you post the logs?

I have turned off firewall and antivirus but the problem persists. My web host insists all my settings are correct. I can connect with FileZilla but it takes more than a minute to do so. I am reminded that this is why I switched to WinSCP probably about five years ago. In consultation with my web host we had WinSCP running fine earlier this week but it stopped working overnight without my having made any changes.

Please post logs from both clients.
Also, this might be a firewall or an antivirus issue. For a test, please try to turn off both temporarily.
See also Why is WinSCP not able to connect to a server, when other clients are?

Hi Guys
I've been having trouble connecting in the past few weeks despite years of reliable use.
I am using WinSCP v.5.21.7 on Windows 8.1
When attempting to connect with SFTP I get the following responses:

Searching for Host
Network Error: Connection timed out.

My web host confirms that my settings are correct. I can connect using FileZilla but I consider WinSCP the superior product so I'd like to continue with it. I've not changed any settings in recent weeks. Grateful for any advice.