Alarm BroadcastReceiver is never called

Question

As the title says my broadcast receiver is never called.

I'm at my wits end, I know there are 30.. thousand posts about this, and I swear I have read through most of them and tried a dozen things but I am either missing something obvious or I have a weird problem.

Nothing is crashing, there are no errors or warnings.

Here are the relevant portions of my Manifest:

    <receiver android:name=".AlertReceiver"
        android:enabled="true"
        android:exported="true">
        <intent-filter>
            <action android:name=".AlertReceiver"/>
        </intent-filter>
    </receiver>

<uses-permission android:name="android.permission.SCHEDULE_EXACT_ALARM" />
<uses-permission android:name="android.permission.USE_EXACT_ALARM" />

Here is the creation methods in my MainActivity:

private void startAlarm(Calendar c) {
    AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
    Intent intent = new Intent(this, AlertReceiver.class);
    PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 1, intent, FLAG_IMMUTABLE);

    if (c.before(Calendar.getInstance())) {
        c.add(Calendar.DATE, 1);
    }

    syncAlarm(this, c.getTimeInMillis(), alarmManager, pendingIntent);
    alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, c.getTimeInMillis(), AlarmManager.INTERVAL_DAY, pendingIntent);
    Log.d("MainAcitivy", "Created Alarm")
}

private void syncAlarm(Context context, long time, AlarmManager am, PendingIntent pending) {
    Intent intent = new Intent(this, AlertReceiver.class);

    if (Build.VERSION.SDK_INT >= 23) {
        // Wakes up the device in Doze Mode
        am.setExactAndAllowWhileIdle(AlarmManager.RTC_WAKEUP, time, // time in millis
                pending);
    } else if (Build.VERSION.SDK_INT >= 19) {
        // Wakes up the device in Idle Mode
        am.setExact(AlarmManager.RTC_WAKEUP, time, pending);
    } else {
        // Old APIs
        am.set(AlarmManager.RTC_WAKEUP, time, pending);
    }
}

And here is my Broadcast Receiver:

public class AlertReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {

        Toast.makeText(context,"AlertReceiver called", Toast.LENGTH_LONG).show();
        Log.d("Broadcast Receiver", "Entered onReceive");

    }
}

Thank you for your time.

EDIT: Okay so turns out it is technically working, but it only seems to trigger when i do a dance I havent quite figured out where I lock and unlock my screen after it has passed the time when the alarm should have triggered. It doesnt trigger if I leave the app open. I think I must be missing a setting.

Answer 1

Well I found the problem:

Note: as of API 19, all repeating alarms are inexact. If your application needs precise delivery times then it must use one-time exact alarms, rescheduling each time as described above. Legacy applications whose targetSdkVersion is earlier than API 19 will continue to have all of their alarms, including repeating alarms, treated as exact.

I played around with some exact alarms and it worked well, just had to dig a bit deeper into the documentation to find that what was on the surface was a lie.