I am having trouble changing the name of a shape in excel for mac.

Example: I inserted a rectangle which is automatically named "Rectangle 6Untitled.png". I want to change the name to "Reg1". When I select the rectangle and go to change the name in the text bar then hit enter, it takes me to the cell REG1 and does not rename the shape.



How can I change the name of a shape in excel for mac?