CFNetwork SSLHandshake failed (-9824) iOs9

I tried to implement a connection on my app to my local server with TLSv1.2. I’m using ionic v1.7.15 and OpenSSL 1.0.2h with Flaskv0.11.1 as bakend server. My erros are:

CFNetwork SSLHandshake failed (-9824) NSRULSession/NSURLConnection HTTP load failed (kCFSreamErroDomainSSL, -9824)

I’m using ionic, and all changes in info.plist file does nothing. This is how I do my request in angularJS:

this.getFriends = function (status) {
    return $http.post('/api/user/friends', {state: status}).then(
        function (response) {
            if (response.status == 200) {
                return response.data.friends;
            } else {
                return [];
            }
        }
    };
};

To deal with my backend server, i had to set a proxy in ionic.project:

"proxies": [  
{  
    "path": "/api",  
    "proxyUrl": "https://172.20.10.3:5000/api/"  
}]

I already tried lots of solution like : NSAllowsArbitrary load to true on NSAppTransportSecurity or add my server ip with other keys like : NSExceptionMinimumTLSVersion, NSExceptionAllowsInsecureHTTPLoads, NSExceptionRequiresForwardSecrecy, NSIncludesSubdomains, NSRequiresCertificateTransparency … i add whitelist cordova plugin to my project too but nothing works.

I don’t know what is the problem. Thanks for the help.