Just as a reference to @deadsuperhero 's experience: I can report similar behavior on my #WordPress#Blog @mediathekperlen . It takes up to 5 minutes to process +/- 1600 followers for posts with no media other than the featured image (max. 1280x720px). WordPress freezes and even has Nginx to throw "not available" messages.
Not too big of a deal, since it recovers nicely after a while.
Server details attached. (VPS on Ionos)
