That is an interesting behavior that is occurring with Extract API. What flavor of Linux are you using?
This is on an EMR cluster in AWS, which is based on CentOS 7 (but then Amazon-ified).
I've had to resort to running this on Windows for now due to this problem (and the problem of single character column names), but will keep trying to resolve this on that AWS system.
My latest suspicion is it might be to do with port access permissions, where Linux does not allow non-root users to bind to ports below 1024 - I'd seen another a couple of forum posts here where users got this to work running as root. Do you know the port number used by the extract API - that may help in the diagnosis?
Sorry for the delay in my reply. I do not know the ports that the extact API uses off the top of my head.
Let me dig a little and see what I can find.