While using Patreon plugins like Patron Plugin Pro or the free plugin, caching at your own WP site or your web host’s server can interfere with the unlocking process and show stale, locked content to patrons who attempt to unlock your content.
Make sure that your caching plugin is not caching content for logged in users if you have a caching plugin at your WP site. Also contact your web host and confirm whether there is server-side caching at your server and whether this can interfere with your users unlocking content.