I would check whether there's a Firewall or any traffic monitoring between the WFA server and the filers.
This is not releted to the WFA platform directly but a networking event.
Also bear in mind that if you suspect that the failure is momentarily - You can go to execution statues and try to resume the workflow: It would retry the same failed command (From it's beginning, so if the command did something you may need to clean that).
Has this issue been resolved?If yes, please could you provide the resolution.I've see at least one more related discussion, it would be a good reference point going ahead for customers facing similar issues.
Out of curiosity, how often do you see this issue?