Terminator: Dark Fate had strong buzz from the beginning, since it brought back franchise stars Linda Hamilton and Arnold Schwarzenegger. As a producer on the film, James Cameron also returned, and took on his first hands-on role in the series since the early 1990s. He had a strong vision for where Terminator: Dark Fate should go, which often was at odds with Tim Miller’s. And he explained that the had some intense disagreements regarding everything from major plot points to minor pieces of dialogue. As a result, Tim Miller was blunt when asked if he’d work with James Cameron again:
Article source: https://www.cinemablend.com/news/2485510/tim-miller-wont-work-with-james-cameron-again-after-terminator-dark-fate-control-clash