Unpublishing a page in Sitecore results in the page still rendering in the browser, even after the revalidation period. Depending on your hosting configuration, a different workaround may be appropriate.
When Sitecore 10.3 Experience Editor is effectively useless, you cannot preview the changes you are making on the Headless CM. Sometimes it works, sometimes it doesn't. Let's get it to work 100% of the time!