This new lock screen doesn't show up all the time. Maybe 2-3 times per day. I think, but I'm not sure, that it's being triggered by the phone going to sleep. Turning the screen off and on only triggers the normal lock screen. The new lock screen never overrides the default lock screen - it's just over top of it. Also, it looks like if I disable lock screens altogether in settings, the new lock screen goes away.
I've uninstalled all launchers except Lightning Launcher and TouchWiz. LL's lock screen is a separate app that I do not have. I've uninstalled all lock screen replacements that I know of (I only had Widget Locker). I checked the list of recently updated apps to try to figure out if it's a new "feature", but nothing. I've checked the list of running apps, along with apps that automatically start up on load and I don't see anything strange.
Does anyone know of a way I can determine how to figure out what this is? I'd like to get rid of it.
I'm running StockMod ROM 4.3 (rooted). A screenshot is attached.