The sort order for search results appears to have changed dramatically this morning, and the closest match is often several down the list. An example of this is Tata Steel UK Limited. Searching the API with the exact company name last week would get the right match, now it gets TSP Projects Limited.
Similarly Spar (UK) Limited now returns the holding company. Same for Yo! Sushi Limited. Please go back to the old match sorting. It was far from perfect but far better than this. If we search for the company name exactly as it appears in Companies House, it really should be the top result.