Why did umpire warn Shubman Gill after Travis Head's catch?

India batter Shubman Gill took a running catch to dismiss Australia opener Travis Head off Varun Chakaravarthy in Champions Trophy 2025 semi-final. He was warned by the umpire following the catch. The umpire apparently warned Gill as he released ball too quickly after the catch. As per laws, fielder must be in complete control of ball after completing the catch.