The issue also impacts the old legacy opensearch API, ( T296225) however that can be fixed by changing query parameters.
The API https://en.wikipedia.org/w/rest.php/v1/search/title?q=Tale%20of%20two%20cities&limit=10 returns redirect titles rather than resolving them.
In new vector we introduced thumbnails and article descriptions for the search autocomplete results. For pages with redirects we show the redirect in the autocomplete results, rather than the page itself, which makes for a somewhat confusing experience because the redirects don't have thumbnails or descriptions. For example:
|what I see||what I expect to see|