new page > sidebar problem

Hi,

It appears, whenever I trie to make a new page, there is a sidebar, even though I think I’ve tried everything in “Customise”. The sidebar is blank now, because I’ve removed all widgets, but there is an ugly empty space there:
https://delevensboom.timvrancken.be/ritueelbegeleiding/

and it should me more like the other pages, as in: https://delevensboom.timvrancken.be/nieuweaardealchemie/

Some advice?
Thanks,

Tim

The page I need help with: [log in to see the link]