411 Length Required response

Summary

Length required in POST request. Content-Length header seems to be stripped by proxy

Content

I'm sending a POST request to the following service using basic authentication.

https://cegbusc-p6.oracleindustry.com/sync/rest-service/dataservice/runquery?configCode=syncP6

I receive the following response:

 "type": "HTTP://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.1",
 "status": 411,
 "title": "Length Required",

When checking the response header it seems that content-length is not a permitted header when using the proxy.

vbcs-proxy-blocked-headers: Content-Length

Is this in fact the case and is there any way around this issue?

NOTE:  I am able to successfully POST this request through Postman.  It adds the content-length header by default.