Thanks for your report.
I have sent you an email with a debug version of WinSCP to the address you have used to register on this forum.

In my workspace I have open two connections, one SFTP and one WebDAV.
After wakeup from hybernation, which I usually involve at the end of working day, the SFTP connection is lost (that's normal), but WinSCP hangs when trying to reconnect and I have to kill the instance. It didn't in former versions.
When going to hybernation with WebDAV tab opened, after the wakeup from hybernation I can work until I switch to SFTP tab. WinSCP then hangs in reconnection process.
The main problem is, that I always have up to some 20 or 30 files open for editing and I always lose my changes on them.

My WinSCP version is 5.13.3 (Build 8565), running on Windows 7 Pro.
Don't know exactly the former, working version, but it was one without WebDAV support (which was the reason for update).

The connection information is:
File transfer protocol = SFTP-3
Cryptographic protocol = SSH-2
SSH implementation = OpenSSH_6.6.1p1 Ubuntu-2ubuntu2.10
Encryption algorithm = aes
Compression = No