No screenshots available…maybe try attaching again. The following is my understanding:
When you allow someone to edit My Tasks (by Sharing it), that is access to the space only. This access does not override the permissions of a private Project.
So, they will not necessarily see all your tasks - only those in a Project they have access to (either via their Team membership, or having the Project explicitly shared with them), or those they are a Collaborator on. So please check their permissions to the Task itself…they need additional access to be present, not just the “Jon’s My Tasks” access. Hope that helps!