I'm sorry, but the knowledge sources do not contain explicit information about why the group key setting item might not be displayed in the project settings. The documentation only describes how to add and configure group keys once the option is available, but does not mention troubleshooting steps or reasons for its absence in the UI Group Analytics: Implementation.
If you are unable to see the group key setting, it may be due to reasons not covered in the provided documentation, such as permissions, plan limitations, or UI changes. For further assistance, I recommend reaching out to Mixpanel support.
