Notifications are missing (either always or just sometimes) when adding a new team member to a project.
Any Clarity supported release.
Notifications are only generated when a resource is added or removed to the Participants list. This action is sometimes related to adding a resource to the project (Staff), but this depends on the value for 'Automatically Add Staff Members As Investment Participant'.
This works one-way only: if set, the staff member will be added as participant, but if removed from Staff, the participant will remain unless it is manually removed.
Also, the notification templates describe that this is for participants only (showing all notifications related to 'Projects'):
The notification however describes that "You have been added to this Project". If this is causing confusion internally, this message can be customized to something like "You have been added to this Project as a Participant".