Setting variables from json into a struct have weird results - json

Question

I have something in my code output I don't understand.
My guess is the issue is due to [me of course] ... the usage of both "struct"+"arduinoJson" to store configuration values.
I have made this simple code that only connect to Wifi;
either using hardcoded settings
loadConfigHarcoded(); // Serial print of values: OK, and "WiFi Success!"
either using deserializeJson
loadConfigFromJson(); // Serial print of values: OK, but "WiFi Connect Failed!"
Is there anything I missed ?
The full code :
#include <ESP8266WiFi.h>
#include <ArduinoJson.h>
const char* ssid = "my_ssid";
const char* password = "my_password";
String confJson = "{\"ssid\": \""+String(ssid)+"\", \"password\": \""+String(password)+"\"}";
struct sConfig {
const char* ssid;
const char* password;
const char* host;
};
sConfig config;
void loadConfigHarcoded() {
config.ssid = ssid;
config.password = password;
}
void loadConfigFromJson() {
DynamicJsonDocument docConfig(1024);
DeserializationError err = deserializeJson(docConfig, confJson);
if (!err) {
config.ssid = docConfig["ssid"];
config.password = docConfig["password"];
}
}
void setup() {
Serial.begin(115200);
Serial.println();
loadConfigHarcoded(); // Serial print of values are OK ; and "WiFi Success!"
//loadConfigFromJson(); // Serial print of values are OK ; but "WiFi Connect Failed!"
Serial.print("SSID=");
Serial.println(config.ssid);
Serial.print("PSWD=");
Serial.println(config.password);
WiFi.mode(WIFI_STA);
WiFi.begin(config.ssid, config.password);
if (WiFi.waitForConnectResult() != WL_CONNECTED) {
Serial.println("WiFi Connect Failed!");
} else {
Serial.println("WiFi Success!");
}
}
void loop() {
}