Currently, in the Chat History, the "Load more results" button is hidden by default. See the bottom section of "How Do I Use Chat as a Student." There is nothing intuitive about requiring users to simultaneously press the Shift and Tab keys (Option and Tab in Safari) on the keyboard to make the button appear. Especially now with the coronavirus crisis, it's important that tools be intuitive and easy to use. We have lots of faculty and staff using Canvas who have never used it before.