Deactivating every plugin didn’t have any effect. Reactivating every plugin in a default theme, the site works as it should (just doesn’t look pretty) LOL
Appears it may indeed be a theme issue. Must have been a simple coincidence with the plugin update.
Thanks Steve, while you haven’t solved my issue, you have helped me determine it isn’t your plugin (which IS fantastic).
I’ve got some more work to do I guess.