I believe you have already contacted me via email regarding this problem.
We have run into an issue where we get orphan connections and WinSCP is not able to logoff after doing the dir listing. The problem happens when there are files with different permissions/groups/users/owners of the files and there are many files. If we download and upload the exact same files to a sub folder which will have same permissions/user/group, then we can list and receive files without problems.
The part that is missing in log when it doesn't complete is this part. (Just after the files are listed)
> 2017-11-09 10:18:34.407 Script: exit
. 2017-11-09 10:18:34.407 Script: Exit code: 0
. 2017-11-09 10:18:34.407 Closing connection.
. 2017-11-09 10:18:34.407 Sending special code: 12
. 2017-11-09 10:18:34.408 Sent EOF message
Once a folder has this issue, it is always the problem so it is not intermittent. Same server works fine with other folders at the same time.
I tested with 5.7.7 and 5.11.2 (latest)