You may be using a caching plugin. If so, try clearing its cache in the plugin’s settings. You may see the changes while logged in but not while logged out. That could be because some caching plugins never show cached pages to the admin while at the same time do show a cached (old) version of content to regular users. In some cases, you may see cached pages even while logged in as administrator. Also check your hosting control panel for caching features that might need to be disabled or purged.