The reconnect button normally shows a countdown. If the connection was refused then it shows counting down from some time (typically about 8 seconds in my experience) until the mouse is moved whereupon the countdown time jumps to 30 seconds.
To reproduce: Set up some site which will not connect, e.g. I was able to use 127.0.0.1 over FTP with anonymous login (I know that will not connect on the test machine). Click the "Login" button. Observe that the "Error" "Connection failed" dialog has a countdown in the button. (Image attached.) Move the mouse over the button and suddenly the countdown changes.
Expected behaviour: The countdown in the button should be the correct value and not suddenly change.
WinSCP Version 5.15.2 (Build 9590)
Windows 10 Version 1903 (OS Build 18362.207)[/img]
It's actually by design. This allows the interval to be small for a quick automatic reconnect, yet it allows user to abort the reconnect, even if the user is not quick enough to point a mouse to the OK button.