The Page View sometimes gets a little confused if you have a multi-column area like the header or footer. It will select items within the area, rather than the whole area. You shouldn’t need to toggle the visual helpers. Just go the the Tree panel and select the element that you are placing in the Grid. For example, in the case of the header, it is the topmost div.
That should then make the style attribute button reappear.
You can also use the Visual Editor. Make sure the element you want to place is selected on the Tree or Page View.
Then click the paintbrush icon.
Click the Grid icon in the Visual Editor or scroll down to the Grid Item section
Enter the named area in the input box
Hope this helps! The learning curve is a little steep, but after awhile things will begin to flow