Summary block issue

I have an issue with using the summary block. On one of the pages on a website I'm developing for my customer I've structured summary blocks in a two-column solution on each section. In the edit mode everything seems to be as it should be, but when I save and leave to have a look at the preview the block reverts to a fullscreen single column solution. It even skews the spacing and make the blocks overlap and generally ruin the page. Is it not possible to structure a summary block this way? I do remember doing this kind of solution on a different project without any issue, so I'm curious on why it is an issue now.

*Edit: I've uploaded a few screenshots to illustrate the issue

Appreciate all help I can get,
Martin.

If you post the link to your site we can most likely help you.