Hi patvandenbosche
This issue often relates to the wrong HTML markup and it breaks the layout.
I tried to inspect elements on this page and it seems the categories part cause this issue:
I tried to temporarily disable these categories but it keeps showing on frontend, I'm not familiar with this extension (it's 3rd party extension), could you try to disable this list and see how it goes?
I also tried to assign another section of sobipro for that menu item page (ID:239) to test with other section but it still saves the 'Chamber of commerce' section: