@jvk hello, reset all settings, it could be a less worked option, to try to solve the problem. The settings and configurations of the apps will be restored, but you do not lose personal data. Greetings
@jvk: Before you resort to a Factory Data Reset, please try checking the following.
1. Settings > Notifications > Included apps > Select 'All apps'
2. Settings > Notifications > Do Not Disturb > Hide notifications, and toggle off any active options
3. Settings > Notifications > Advanced settings > Show notification icons > All notifications > Floating notifications > Select 'Bubbles' or 'Smart pop-up view'
4. Settings > Apps > Select an affected app e.g. Messages > Notifications > Show notifications > On.
Let me know if this helps. If you do decide to perform a Factory Data Reset, then please take a look at the guide below, including how to back up your personal data.
Check That Do Not Disturb is not enabled. It may seem obvious, but forgetting Do Not Disturb is enabled is one of the most common causes of not receiving notifications. If this setting is on (enabled), turn it off, and they will start working again. Restart your phone