If you setup the notification system under Settings > Notification Settings
Then it should of notified you of the errors on the drive... I would need to test myself though
Edit: After pulling my disk 5, I got a notification within 5 seconds (Discord) This is what my main screen looks like too:
After this I stopped the array, unassigned the device, started the array. Then stopped the array and reassigned the device and started the array.
Data is now rebuilding fine.