Group Focus not available on Reusable element

Hi, newbie here!

I know this topic might be mentioned before but I can’t find the solution to it.

I created the header and I added the Group Focus to it for mobile view menu bar. As soon as I turn my header into the Reusable Element Group Focus becomes unavailable.

I am aware that “MaterialIcon menu” gets nested into the Reusable Group but I can’t find the way around it to make it work…

How can I create the Group Focus menu on the Reusable Header?

I appreciate your help.