APIcast returns 403 (unauthorized) when the credentials are valid and CORS (Cross-Origin Resource Sharing) properly set on Red Hat 3scale API Management

Issue

We published an API in 3scale and we can't access to it through an angular front which is doing api calls. However using Postman or curl we are able to receive the expected response. If I deactivate my CORS I got the issue of host not allowed. If I active my CORS the gateway is unable to receive the token. Here's the output of the log:

2018/09/28 15:13:30 [info] 22#22: *13 [lua] proxy.lua:71: rewrite(): no credentials provided for service 1234567890, client: 10.0.1.1, server: _, request: "GET /favicon.ico HTTP/1.1", host: "10.0.1.2:8080", referrer: "http://10.0.1.2:8080/path/to/url"