There’s a behind-the-scenes shakeup on Katherine Heigl’s upcoming NBC drama series: Showrunnner Ed Bernero (Criminal Minds, Third Watch) is exiting the promising espionage thriller State of Affairs, sources say.

Showrunner changes are not entirely uncommon during the run-up to a series launch and one source close to the project said Bernero had creative differences with fellow executive producer Joe Carnahan. The source further claimed the exit doesn’t have anything to do with the show’s star — who previously departed ABC’s hit Grey’s Anatomy under contentious circumstances. Last month, Heigl denied to reporters at the Television Critics Association’s press tour that she’s difficult to work with.

On the new drama, Heigl plays Charleston Tucker, a CIA analyst who advises the president (Alfre Woodard) on international security while balancing her complicated personal life. Writer-producer Dario Scardapane (FX’s The Bridge) is in talks with NBC to takeover showrunner duties on the series. State of Affairs airs Monday nights this fall starting Nov. 17 on NBC with a lead-in from The Voice.