Bug Can't apply force to Rigidbody that is attached to a fixed joint

I have a game object with a rigidbody. I apply a force and it works correctly.

I add a child object with a hinge joint. When I run it the child object does not stay attached to the parent.

I added a fixed joint to the child object and use the parent object for the Connected Body.

This now causes the child to stay attached. Now when I apply a force to the parent it does not work.

How can I use the joints and apply the force to the parent?