one column not possible

Hi I am trying to make one particular page into just one single column, by choosing the ‘1 column’ layout here: https://screenshots.firefox.com/Jyxrcj1Iuu9esUcO/akikolingoland.com

I remember at the beginning of using Hueman it used to work, but since a couple years ago no matter how I try it just doesn’t work. Please help ASAP?

Thank you!