It's possibly this bug:
https://winscp.net/tracker/1498

Can you send me an email, so I can send you back a development version of WinSCP for testing? Please include link back to this topic in your email. Also note in this topic that you have sent the email. Thanks.

I'm using WinSCP version 5.9.3 (Build 7136). It's really annoying to have to type my password in over and over again. Any word on a fix?

Thanks.

Thanks for your report.

Can you send me an email, so I can send you back a debug version of WinSCP to track the problem? Please include link back to this topic in your email. Also note in this topic that you have sent the email. Thanks.

WinSCP 5.9.1
Problem started after upgrading from WinSCP 5.7.7 (Build 6257)
windows 7
Transfer protocol = sFTP
When logging into WinSCP, there is a checkbox "Remember password for this session". Checking this box enables an automatic re-login when the current session expires.

After upgrading to WinSCP 5.9.1, the checkbox no longer does anything. And besides having to enter the password after every expired session, the initial login fails, you have to click the Reconnect button and enter the password for a second time before the login will complete. Issue also occurs with WinSCP 5.9.

As soon as I reverted back to WinSCP 5.7.7, the checkbox returned to working as expected.