Need to maintain a long connection

Long connections often exit

It takes a long time to reconnect every time

Especially for servers with slow network speeds

Always waiting for a long time on this interface

Need to maintain a long connection
Even if it wastes network resources

Did you try to enable keepalives?
https://winscp.net/eng/docs/ui_login_connection

I regularly maintain SFTP connections for several days and even weeks. If keep alive doesn't work I would assume your ISP or the fact your connection is bad is the culprit.

Enabling keepalives usually works for me too. If the connection still drops, it could be the server settings or network issues. You can also try adjusting the interval for keepalive signals to a lower value for better stability.