We have now identified this problem with a few our customers. The following solution only applies if you are using a CDN like CloudFlare, Akamai or similar.
All our WordPress products rely on the new technology coming with WordPress Core 4.7: WP REST API (read more about it here). In most cases there are no problems with WP REST API and a CDN, but if you have a special configuration, data may be loaded “out of date”. If you are technical and you have a look at your network requests (F12 > Tab “Network”), you will see that Cloudflare handles caching also for WP REST API requests:
This is fine, but for some configuration this can lead to “outdated” data scenario.
Why other plugins does not have this issue?
The answer is simple, a lot of plugins out there does not rely on the new core technology of WordPress’ WP REST API. It still uses the old `admin-ajax.php` mechanism which is “deprecated” through WP REST API.
Why e.g. Real Media Library does not work?
Real Media Library (and all our other WordPress products) rely on the new WordPress technology WP REST API, so all network requests are served through e.g. https://example.com/wp-json/realmedialibrary/v1/tree
What do I need to do now?
Configure your CDN to bypass caching for https://example.com/wp-json/*