Box Search API case-sensitive query param

We use 'search for content' API and I was wondering if any recent changes happened to the query param of this API. IIRC, we used to pass a case-insensitive param even for the key-words like AND, OR & NOT and it used to work fine even if we pass lower-case keywords. But it is no longer working that way.

When I checked the documentation, it states that keywords has to be passed in upper-case only. Reference: https://developer.box.com/reference/get-search/#param-query

Is this a recent change?