I have two separate OJS 220.127.116.11 installations for two journals on the shared hosting account.
I enabled Memcache for both of them and then the contents from the two journals started to mix! Some of the articles from one journal were shown on other journal’s website.
Also, homepage on one of the journals was showing archival, rather than the actual selected current issue.
I disabled Memcache and everything went back to normal.
I have the Cloudflare CDN enabled on my hosting. In addition, my hosting company (Siteground) has some own caching.
Is this a bug with Memcache? Are you interested in evaluating further this issue?