If you have a SharePoint task list where the task is assigned to a SharePoint group, you may notice that the My Task list does not show tasks even if you are a member of the group of which the task is assigned.
Fortunately, there is a simple fix. It does require SharePoint Designer though. Open SharePoint Designer and then open the My Tasks view of the task list in code view. Find the <where> tag and within it add the following:
Save the view then open it again in the browser. It should now show any tasks assigned directly to you as well as any tasks assigned to groups of which you are a member.