Change on Request requires that significant changes, opening a new browser window, automatically submitting a form when a field’s value changes, redirecting to a different page, happen only in direct response to a user’s explicit action, with the option to turn off any automatic changes elsewhere permitted by other success criteria.
Auto-submitting dropdown filters that navigate the page the instant a user selects an option are a classic failure, since a keyboard or screen reader user arrowing through options can trigger an unwanted navigation before they finish deciding.