The Hidden Alerts
macOS features a robust Notification Center that slides out from the right side of your screen. To prevent a single busy app (like a group chat in Messages or a flood of emails in Mail) from taking over the entire screen, macOS automatically groups notifications by application. Instead of seeing 10 separate email alerts in chronological order, you see one stack of emails that you must manually click to expand. While this keeps the Notification Center tidy, it makes it very easy to miss important, time-sensitive alerts buried at the bottom of a collapsed stack.
Ungrouping Your Notifications
To ensure you see every alert individually and stop macOS from automatically grouping notifications by application, you must change the sorting behavior within the system settings.
Click the Apple logo in the extreme top-left corner of your screen and select System Settings. In the left-hand navigation sidebar, scroll down and click on Notifications. In the main panel, you will see a list of every application installed on your Mac that is capable of sending alerts. You must adjust this setting on a per-app basis. Click on the specific application that is hiding alerts (e.g., Messages). Scroll down to the bottom of its specific settings page until you find the option labelled Notification grouping. By default, this is set to “Automatic” or “By App.” Click the dropdown menu and change it to Off. All future notifications from this app will now appear individually in your Notification Center, sorted chronologically.