If you are not getting apps notification in Android device until you unlock the screen, maybe this is due to When your device goes into sleep mode it disables your Wi-Fi which stops data syncs of apps.
How to Keep Wi-Fi Enabled at All Times.
1. Open Android device settings and Tap on Wi-Fi. It will open Wi-Fi page which shows all the available networks and settings options.
2. Tap on the Gear icon at the top right corner. It will open Configure Wi-Fi settings.
3. In Configure Wi-Fi you will find the option “Keep Wi-Fi on during sleep“, tap on it and select Always.
That’s it and you are done here, now onward your device Wi-Fi always on whether your device is sleep or not. Like this article please share and read more QuickTip.