Ionic Push Notifications Don't make any sound / status on Android

Hi all. I’m creating an app with Ionic. The Android notifications, by using the https://push.ionic.io/api/v1/push is indeed reaching to my android application, but there is no sound / status bar / notification on my device. Nothing. So when my application is not active, the user doesn’t have any way to know that a push notification has arrived. What should I do?

I tried configuring every parameter possible:

var push = new Ionic.Push({
“debug”: true,
“canShowAlert”: true, //Can pushes show an alert on your screen?
“canSetBadge”: true, //Can pushes update app icon badges?
“canPlaySound”: true, //Can notifications play a sound?
“canRunActionsOnWake”: true, //Can run actions outside the app,
“pluginConfig”: {
“ios”: {
“alert”: true,
“badge”: true,
“sound”: true
},
“android”: {
“icon”: “resources/android/icon/drawable-ldpi-icon”,
“iconColor”: “#ff00000”,
“vibrate”: true,
“forceShow”: true,
“sound”: true
}
},

But nothing helps.
I wonder if I should programmatically make a sound in my application? Should I programmatically change the status/notification bar?