If your homepage search bar, availability calendars, and booking widget all stop working at the same time on a SiteGround-hosted site, the cause is SiteGround’s Speed Optimizer plugin.
Why this happens. All HomeRunner interactive components are powered by one large script library. The JavaScript minification in Speed Optimizer can fail on this library, and when it fails, it saves an empty file in place of the real one. Because every interactive feature depends on that one library, they all stop working together, across your whole site rather than on a single page.
How to recognize it. In the browser console, you typically see ‘Uncaught ReferenceError: hkUIkit is not defined’.