Patron changed tier and now can't see anything

My patron first signed up for my $18 tier, and then minutes later changed to a $25 tier. But now when they go to my site, everything is locked, so they’re not seeing any locked content at all. They should be able to see public content, $18, and $25 content. Help, please?

First ensure that your site is not caching stale pages and is showing old cached pages to your users. This can happen at three places: at your site due to your caching plugin, at your server due to host caching, and at cloudflare etc due to aggressive caching.