Parsing issue | Transfer-Encoding: chunked

[muq_ash]

I have a target endpoint which is up and running. When I try to map the endpoint on Apigee, I am getting junk response with 403 http status code as follows:

My assumption as per this article is that the error is occurring because Apigee is unable to parse the Transfer-Encoding: chunked header. The response headers of the target are as follows:

If we are unable to remove the header or set it to any other value, what could be the way around? How else can we get 200 response from the target?