Random Blank Pages in cache

I’ve been running W3TC on many sites for years, but a problem has come up in the past few weeks that I can’t track down. Seemingly randomly, a blank page is generated and saved into the page cache, and then all future requests end up with this blank page. A view-source shows that the page is completely empty. If I purge the post from cache, it fixes it. If it affects the homepage or a category, I have to do a full flush of the page cache.

It happens to 7 to 10 posts per day, and I can’t reliably reproduce it. And there is nothing unusual in the error logs. I’m running WP on multiple servers, and using W3TC for page, database and object cache using memcached.

Has anyone else had this problem? Is there a way to trigger W3TC to not serve the cached page if it’s empty?

Thanks!

Joe

https://wordpress.org/plugins/w3-total-cache/