The following are reasons why notifications may show as delivered on the Messenger dashboard but are not visible on your device or website -
The app is currently In Focus
By default, notifications will not be displayed on the device if your app is currently "in focus" (open and visible).
The App is Force Stopped
When an app is in a "Force Stopped" state most events including GCM/FCM messages for push notifications will not be received. An app can be placed in this state in the following ways.
> From Settings > Apps, "Force Stop" is pressed.
> Long pressing the back button on some devices.
> Using a 3rd party task killer like Greenify.
> Swiping away your app while remote debugging it.
> Not the same as viewing the logcat but launching your app as a remote debug process.
> Swiping away your app from the from the recent apps on list on a Xiaomi device.
> Automatically on some devices due to custom Android tweaks done by manufactures. Steps below on disabling this.
Huawei - Only Pre-EMUI 5.0 / Android 7 - Go to Settings > "Protected apps", check your app. Full Instructions
Sony - Tap on the battery icon. Go to Power Management > STAMINA mode > Apps active in standby > Add your app
Asus - Check your app in the Auto-start Manager
Xiaomi - Security (App) > Permissions > Autostart - Enable your app
*New Xiaomi - Settings > Developer Options. Disable "memory optimization". To enabled Developer Options go to Settings > About. Tap on MIUI 8 times. Full Instructions. For additional Information , click here .
Redmi - Same as Xiaomi
Oppo - Go to Settings > "Security settings" > "Data saving" and enable your app. For additional information, click here .
Samsung - Disable battery usage optimizations
Action buttons or iOS 10 media are set and requirements are not meet
The app must be not force killed and the correct settings must be enabled when these options are set.
The app has push permissions Disabled
iOS - Check your app under Settings > Notifications.
ANDROID - Check the notification setting under Settings > Apps
You have network issues
The network / WiFi you're connected to may have closed your connection to Apple or Google servers'. Try disabling and re-enabling your internet connection. See our Notifications delayed troubleshooting guide for more details details.
The browser is Full Screen
Make sure the browser is not in full screen mode, which prevents web push notifications from appearing.
Only In the following browsers we are currently supporting web push
Chrome: 50 and above
Firefox: 44 and above
Opera Mobile: 37 and above
Web push Big Image only works for chrome 56 + in windows os , linux os , android mobile, not in iOS devices
Learner is using Incognito / Private Browsing mode in browser, which doesn't support web push
web push only work in https enabled web site