Same thing happened to me, except that the theme appearance was killed, not the whole site completely. Turned off the plugin too for now. BTW it happened right after I cleared the cache
I just had the same very problem, but turned out that after deleting my browser cookies it got applied for all the posts. So it wasn’t really a theme issue, but a browser issue (i.e. the rest of the users, at least new ones, saw the website correctly). Was your resolved in the same way? Or you had something else to do?
