Seems like most if not every app will ask for permission to show notifications. I'd recommend checking all important apps and make sure they are re turned on! Didn't realize this and didn't get notified about some emails.
Did you lose any of notifications settings from One Ui 3 after upgrade to One Ui 4 ? Resetting device would cause this behavior, Please let us know if you reset the device if settings have changed. In case of no reset being performed on the device, please send us an error report from the Samsung members app -> Beta Feedback -> Error Reports as notification settings should be carried on from One Ui 3 to One Ui 4.
