Meghan Markle and Prince Harry recently lost another staffer — the Duke of Sussex’s chief-of-staff, Josh Kettler, stepped down from the role after just three months — and it might be the former actress’ fault, according to a source. “It’s Meghan. She’s unbearable. She talks down to people and is very condescending,” a source told NewsNation. In 2021, the former actress was accused of “bullying” royal staffers, but she adamantly denied the allegations. A spokesperson called the assertion “a calculated smear campaign based on misleading and harmful misinformation.” Leading up to Meghan and Harry…