Are you sure your ic_notification exists in the drawable directory?

Add this to your main activity :

<intent-filter>
    <action android:name="android.intent.action.VIEW" />
    <category android:name="android.intent.category.DEFAULT" />
</intent-filter>

This should always redirect the users to your app instead of settings

Also sometimes its tricky because permissions are messed up when you are simulating vs actually running it locally on a device

Add this to your <service> tag : 

android:name="com.ryanheise.audioservice.AudioService"
    
android:foregroundServiceType="mediaPlayback"
    
android:exported="true">

Make sure "AndroidManifest" includes :
<uses-permission android:name="android.permission.FOREGROUND_SERVICE_MEDIA_PLAYBACK" />

Should fix the issues you have, but also make sure that you don't have local and flutter notifications conflicting, check your flutter_local because remember its not a simulation when its local :)