Settings can be adjusted in the toolbox on the left side of the editor. You can adjust:
In this setting, you can adjust how the multicolumn spacing will be when viewing on mobile.
If you adjust the ''Top'' settings here it will create a space visible only on mobile view.
When you go to ''Preview'' mobile, and choose ''Mobile'' you will see the space.
Left and right spacings are not rendered in mobile in order to make your content wider on smaller screens. If you would like to use the same spacings on desktop and mobile views, please add a Box, adjust its paddings/margins and drop your Multicolumn into that Box.
Let us know if you have more questions!