protocol.http.UnsupportedEncoding

Below is the debug trace...Please share your thoughts as how can we resolve this issue.

com.apigee.errors.http.user.UnsupportedMediaType: Unsupported Encoding "UTF-8"
  at com.apigee.protocol.http.msg.Encoding.wrap(Encoding.java:87) ~[http-1.0.0.jar:na]
  at com.apigee.protocol.http.msg.Encoding.wrap(Encoding.java:52) ~[http-1.0.0.jar:na]
  at com.apigee.protocol.http.HTTPClient$Context$3.onHeaders(HTTPClient.java:1039) ~[http-1.0.0.jar:na]
  at com.apigee.protocol.http.io.MessageReader.onRead(MessageReader.java:119) ~[http-1.0.0.jar:na]
  at com.apigee.nio.channels.DefaultNIOSupport$DefaultIOChannelHandler.onIO(NIOSupport.java:51) [nio-1.0.0.jar:na]
  at com.apigee.nio.handlers.NIOThread.run(NIOThread.java:123) [nio-1.0.0.jar:na]

As expected based on the error message I am able to track the issue via tcpdump as the response from backend having header with

Content-Encoding: UTF-8 which apigee is not appreciating. Can some one detail on what is happening?

As per spec it show as below..

https://tools.ietf.org/html/rfc7231#section-3.1.2.2
==
The "Content-Encoding" header field indicates what content codings
have been applied to the representation, beyond those inherent in the
media type, and thus what decoding mechanisms have to be applied in
order to obtain data in the media type referenced by the Content-Type
header field. Content-Encoding is primarily used to allow a
representation's data to be compressed without losing the identity of
its underlying media type.
==

Below is the headers when the issue occurs. Content-Type and content (json) matches . Wondering what is the issue.

Content-Length: 404
Content-Type: application/json; charset=utf-8
Last-Modified: 2017-09-08T17:10:46.451-06:00
Content-Encoding: UTF-8
Allow: GET, POST, HEAD, PUT, DELETE, OPTIONS
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