Kevin Costner isn’t coming back to Yellowstone after season 5, according to a report from Entertainment Tonight. The star, who helped turn Yellowstone into a phenomenon, will reportedly leave the series after the season that’s currently in production.

This reported split comes after months of rumors and reports of feuds behind the scenes of one of the most popular shows on television. According to reports, the series co-creator Taylor Sheridan had concerns over Costner’s commitment to the filming of Yellowstone’s fifth season.

Part 1 of Yellowstone’s fifth season has already aired, but the second half hasn’t been completed and doesn’t have a release date yet — and according to Entertainment Tonight, it’s unclear when the cast and crew will return to work on the new episodes at all. Among the rumors about Costner’s commitment to filming part 2 of the season was that he only made himself available for one week of filming, something Costner’s lawyer denied.

Despite Costner’s undeniable star power and its key role in getting Yellowstone off the ground, the series, and Taylor Sheridan’s larger TV empire, has since gone far beyond its original star. The Yellowstone universe alone has five spinoff series so far, with stars like Harrison Ford and Helen Mirren, and more on the way, including a series starring Matthew McConaughey.

Still, with production stalled on season 5’s second part, it remains to be seen what Sheridan and his team’s solution will be for dealing with Costner’s apparent absence from the Yellowstone universe’s flagship show — or even if that show will continue without its first big star.

Polygon has reached out to representatives for Costner and Paramount for comment and will update this story when they respond.