Hello,
first of all sorry for my uppercase text in title, i dont want to create problems.
Howewer, i fix the bug: is not necessary use the sandwich builder (that is not good like site origin or visual composer).
To fix the “bug” is sufficient set the gutter (distance between columns to 20px instead of 30/35px).
I have test both with site origin builder and visual composer of themeforest and with this setting the problem is resolved.
Using the right words, this is not a bug, because it depends only by the content margin in mobile view that are very little instead of other wordpress themes.
If you increase with an update the margin left and right of page content of 5 pixel each, every page builder will works fine with your theme and i think that this is very important because the best and most used page builder is the siteorigin.
Thanks and best regards.