I have tried clearing Autoptimise and WP Fastest Cache, I can’t disable them on a production site. I don’t think it’s that because other layout element changes work fine.
No other layout elements are added on the site.
Could it be that I need to apply the larger container site-wide and then use a layout element to make it smaller on all pages except this one?
UPDATE: the element works fine as long as the site-wide container is wider than the one defined by the element. But then the top menu bar is far too wide. How can I work around this?