I'm not entirely sure what code I need to attach for this question but basically on this site (https://www.great-days-out.co.uk) if you search using the search box in the footer the search page bugs out after a few articles.
From inspecting element it looks like the line closes before going through all the articles.
I haven't got a search.php file in my child theme since I feel like this is an issue with another file but I have no idea where to start looking.
Right, I see an extra
</div> or two after each article. Can't really tell what's generating these but last time it happened to me I had just left a closing
</div> tag in functions.php where I'd meant to delete it.
I'd go through any .php files you've made / altered that affect this page, just do a cntrl + f search for
</div> — you'll probably see one or two which don't line up with an opening
<div>. It's not necessarily search.php, could be a custom partial or something.