For some reason I can’t set my homepage and several other pages as full width. It was full width till I changed the Page Settings to select a sidebar. I have since changed it back. But I have lost my full width pages. All boxed. Even if I go inside the individual page and scroll to the bottom and select ‘Full width page’ I still have a boxed wrapper for the page making a mess of it. I have cleared the cache several times. Also took all the widgets out of the Page Sidebar Area.
I solved the problem. On the backend of the individual page under ‘Page Attributes‘ on the right select the correct theme from the dropdown. Hopefully this helps someone else. I had ‘Default Template‘ which worked no bother till I started adding widgets to sidebars. ‘Visual Composer Template‘. I now have full width on my pages again.