Why are notifications not displayed (Messenger, Instagram etc)?

Question

Android

FB Messenger Notifications Not Showing
Here's what else I've seen:

1. notifications are displayed normally immediately after installing the messenger - at the same moment a bunch of undisplayed notifications from Instagram appear (it seems that they were hanging in memory, but they were not displayed and surfaced after something happened)
   
2. Notifications stop showing after rebooting the device
   
3. notifications start to be displayed after the messenger is moved to the SD card - at the same moment a bunch of undisplayed notifications from Instagram appear (it seems that they were hanging in memory, but they were not displayed and surfaced after something happened) . Notifications disappear after reboot
   
4. Telegram works quite adequately in terms of notifications
   
5. Notifications from Gmail come somehow in batches: either empty, or a notification about a bunch of letters will come, although earlier notifications came as new mail arrived
   

no services were disabled, not deleted,
cleared the cache and data
, it seems to me that the problem is somewhere at the level of android services - the notification service is dull and does not display notifications that
Factory reset applications give it, I don’t want to do it. it will be necessary to cut a bunch of applications (some of them are not from the market) and it’s not a fact that a factory reset will help the
device: Lenovo A820, Android v4.1.2
Update 1
Andrey advised the user a utility that changes the heartbeat of networks in order to revive notifications, but it did not help. but I figured out that push notifications do not work. it seems that the service that listens to these notifications from third-party services is not working

Answer 1

Try this https://play.google.com/store/apps/details?id=com....