Roeper — one of a handful of Chicago media personalities with national reach, thanks to his eight years as the late Roger Ebert’s co-host on “At the Movies” — had 226,000 followers as of Monday, down from 253,000 a year ago. During a one-week period in September, he experienced a sudden, unexplained drop of 20,000 followers, quickly followed by a sudden, unexplained gain of 25,000 followers, according to data from trendsmap.com.