Http.post sends get request

Ionic Framework ionic-v3
1

Hi.
I have the problem that I send a POST request, but on the server side I always receive a GET Request
Here my code:

let params = "deviceToken=" + token;
let headers = new Headers({
    'Content-Type': 'application/x-www-form-urlencoded'
});
let options = new RequestOptions({
	headers: headers
});
    return new Promise((resolve, reject) => {
        this.http.post(REST_URL, params, options)
            .subscribe(data => {
                this.logger.debug("response is plain text, no json data)
            }, err => {
                reject(err);
            });
    });
2

I also have a similar problem. But with sending arraybuffer. were you able to fix this?