S21 FE Recently stopped waking screen to display notifications.

[xsherrinTas]

As with the title my S21 FE which has been a great phone up until now has stopped waking, vibrating or displaying anything when I receive a notification.  
This has made life considerable difficult with not just social apps but also work apps.  
The notification icons are there when I wake the screen but I really need a way for me to actually get notified (that's why they're called notifications, right?)

In the "Notifications" setting I have "Notification pop up style" set to "Brief" and "Show even while screen is off" (this is the function that seems to have stopped working recently).
I have all relevant apps set to allow notifications. 
I have all settings in the accessibility setting turned off.

I've tried turning on vibrate and sounds notifications but they also don't work for the apps I need.

I'm struggling to find any online solution.  
I'm pretty desperate for a solution as this pretty much makes my phone useless for its intended function. I have to constantly keep waking my phone to see if I have any messages. 
I'd also like to know if this is an intended update. In which case it is I will have to purchase a new phone and permanently avoid Samsung.

[Troubadour]

Just double-checking. Also check volume settings by going to Settings, scroll to Sounds and vibrations, Volume. Also,in the same area scroll to Notification vibration and Vibration intensity. I suppose you haven't got an active routine set? Although setting a routine might work. For fixed time notifications Google Assistant might be a solution.

[Dinosaur890124]

1. Check if Do not Disturb is on, or a mode routine is causing do not disturb to turn on
2. Ensure Battery saver isn't on.
3. Go into settings, then apps, then find an app that you want notifications from and ensure all the notifications for that app are allowed.
4. Go into settings, then battery, then background usage limits. Ensure that none of the apps you want notifications from are in the sleeping or deep sleeping apps section.
5. Is it all your apps that don't receive notifications?

[Troubadour]

Also go to Settings scroll to Apps, go to 3 dkts top right, click on Permissions manager and search for Notificatiins.

[badazzibbi]

Take it to samsung shop they will fix it

[iftt]

If you have 'nice catch' installed as part of 'good lock' enable it and it should help you see what settings are affecting the outcome of notifications.
Just flip it on and do your thing, after the notification happens all should be revealed.

[_nok_]

Are you using any Galaxy watch?

If yes, you might need to check the Mute connected phone settings.