After installing APO, my wordpress site has been faster, and seems to work well. The problem is, after a day or so, the site will start showing a blank post or two. Not every post, but some of the most popular. I clear the Cloudflare cache and voila, everyone is fine for a few days more.
When I type the url into a browser, it just shows a blank page. It doesn’t throw an error like a 404. Just no content.
Any ideas where to look, how to troubleshoot the problem?
May I just add a notice here, as I remember I have had some issues few years ago with WordPress running without a cache, but had a lot of traffic on it - before we moved to Cloudflare and activated a cache.
It was the origin host/server generating some strange “5xx” errors, none of them were logged into the access or error or even WP debug log file, but the visitors including us the owners/webmaster encountered the strange behaviour where the main homepage or posts pages were “blank” or “white” only, without content, and not all of them.