You are using a caching plugin on your WordPress website.

Using a caching plugin on your website can speed up the load times of your site. They can also be called optimization plugins. It does this by creating static copies of your pages. These are plain HTML pages that do not require a database call to retrieve any information (which is the default process for WordPress sites).

The downside of caching is dat you're looking at an older version (a copy) of your web pages. So the latest changes might not be reflected. Most caching plugins will do a page flush when a page is being saved in WordPress. But thee plugins don't know about NowButtons.

Flush the cache when you make button changes

To make sure your button changes are displayed properly on your website you should always flush or empty the cache after you've made a change to NowButtons (a new button, a change or a removal). That will nearly always solve any display issues.