[pinboard theme] Image/portoflio gallery distorting page layout

Hi,

I’m using the pinboard theme with an added child theme.

In the theme you can add an image preview to your posts and display them on a Portfolio page. However when I do this the new page doesn’t keep the same dimensions as the overall layout, and the width of the new Portfolio page expands. The example is the correct layout https://kidberlin.com/news/ and the portfolio page https://kidberlin.com/books/

Does anyone know what could be causing this, or how to fix this issue so that the portfolio page keeps the same alignment as the other pages on the site?

Many thanks in advance,
Mike