You’ve enabled and disabled UnderConstructionPage so many times that your head is spinning. You see one version of the site, your client sees a different one. Nothing makes sense any more! Although not a common scenario this is definitely something that can happen when cache gets stuck and continues to serve stale content.
This tool takes extra steps to bust trough the cache and display the real, non-cached version of the page. The version that everyone should see, and will see after the cache is purged