How does one hide all redundant columns to the right of one's data?

If I select the leftmost unused column and then press ctrl+shift and fn+right arrow which https://support.office.com/en-za/article/Keyboard-shortcuts-in-Excel-2016-for-Mac-acf5419e-1f87-444d-962f-4e951a658ccd states is the correct sequence at best it highlights only half a dozen or so columns.