404 Not Found when sending FHIR bundle

Everytime I try to send a POST FHIR bundle I'm getting the following response: 404 Not Found. I'm not really sure why, although it works fine with a GET!

This is an example: 

 Response:

It might be something related to request path but not really sure.

And this is the HTTP service I'm using 

I tried this with Postman and it's working as expected

Am I missing something ?