I had another recurrence of an issue I've yet to track down the cause on.
The comments just turned themselves off. They've been doing that every couple weeks or so for a while now. The setting to globally allow comments, and to require commenters be registered are switched (so they now have to register and comments re not allowed globally). Plus all the comments locally on all my specific posts are turned off too, whereas before they were all on.
So my question for @esmi or anyone else, is this. If I deactivate all plugins and revert to the WP default theme, will that throw the switches back on to allow comments? What I had been doing is switching everything back to the way it is first, then deactivating plugins and waiting (which gets messy if you have to deactivate Akismet). Since this problem once I tweak the settings, won't recur for a few weeks, it's hard to go that long on a default theme and no plugins, hoping it does or doesn't recur. How can I diagnose this best? I've discussed this in many other threads but this one is a more recent thread so maybe I can get some help.
I've had this happen I think on the Twenty Ten theme as well as the Staypressed theme. From other forum posts, this is a common bug affecting people using different themes, different sets of plugins and different hosts, but WP isn't offering help, and it's almost impossible to diagnose or troubleshoot because it's so random as to when it will happen.