Running WinSCP via BPM code

Hi all,

we have recently started calling WinSCP via an external .dll, that is being called on update of one of the UD tables. Its been working ok, until we rebooted our app server, after that FTP started to timeout, and the log says unable to connect. But I can definitely connect directly through WinSCP.
We have them rebooted again, and it came back to live and worked ok, until the next reboot next month - same issue.

Does anyone know why its happening and how to fix it?