I believe I had a similar issue, but not certain, see if my notes apply to you … in any case I think you’ll find your answer by look for info on ‘reparenting’ …* reparenting an element will be reflected on ALL layouts, not only cascaded down to smaller layouts. If youve used a grid (like a 2 column grid), and want to downsize it for the tablet break point, moving the element from the right column to the left will be considered reparenting, and will refect to and ruin the desktop layout. Manually adjusting the grid (by 'adjust grid / then deleting a column) will also not work. Do this = / select the container / adjust grid / click on the 1x4 choice (to get down to one column. This will stack the previous colums vertically into one column, wihout ruining / reflecting onto the desktop layout.