tldr; Caching plugins and SomeNano for WordPress plugin do not play well together. Pages that use the SomeNano plugin need to disable caching.
A support ticket was submitted with the observation that once a payment was made to the SomeNano for WordPress plugin, the paywall did not go away. The report mentioned having caching plugins activated on their WordPress site.
After some investigation and testing with the top caching plugins for WordPress, I came to the conclusion that yes, the caching plugins do not play nicely with SomeNano for WordPress.
How Caching Plugins Work
WordPress is a complex engine behind the scenes. Because of this, a caching plugin can take a good deal of load off your server by generating a page, saving a copy of it, and serving that static page to all users that visit your site until you decide to refresh cached page.
This is great for static sites!
This is not so great for dynamic content …
A page that has dynamic content (content that is responsive to a user’s actions) needs to talk to the server in order to generate the most accurate content. A cached page will be handed blindly to the browser, not generated with the input from the user.
If a page/post is cached before payment, all users (even those that pay) will be served the static page with the paywall in place.
If a page/post is cached after payment, all users (even those that have not paid) will be served the static page with the paid content visible.
Can I Still Use Caching Plugins?
You can use caching plugins on your site, but you can not cache a page that uses the SomeNano for WordPress paywall. Each caching plugin is different. Some allow you to designate certain pages, categories, and/or tags that are excluded from caching. But unfortunately I can not support all the various caching plugins as well and will have to leave that up to you.