Meghan Markle apparently was not on her best behavior during a charity polo match/Netflix filming moment in Miami, Fla., on April 12. “She is a very difficult person,” royal expert Angela Levin dished. “And we saw that a week or so ago with how rude she was when Harry was doing his polo.” Prince Harry and Meghan were in Southern Florida to take part in a Sentebale event at Palm Beach, which was also filmed as part of a future Netflix show about polo featuring the Duke of Sussex. “This woman, a very nice, attractive woman in a beautiful white dress moved to stand by Harry,” Levin added. “Meghan…