To reproduce the incorrect quotation marks as shown in the screenshot, the search query needs a space at the end.
The block themes (T23, T24 and T25) use the Query Title block, which surrounds the query with plain quotation marks. When that string runs through wptexturize, the space before the final quotation mark matches the pattern that replaces it with an opening quotation mark.
Search results for: “Kitchen Sink QA Page “
Trimming spaces, at least on the (right) end, might be reasonable.
rtrim( get_search_query() )
To change the Query Title block, please open an issue on GitHub.
https://github.com/WordPress/gutenberg/issues?q=state%3Aopen%20label%3A%22%5BBlock%5D%20Query%20Title%22