XCOM 2 launched to near-universal acclaim last week, but also with a near-universal caveat to that acclaim: it doesn't run as buttery as you'd expect a turn-based strategy game to, even on high-end hardware. Some players, including most of us on the PC Gamer team, have reported dips in framerate and hitching, especially during camera movement and in-engine cutscenes. Criticism of the issues has found its way onto two of the usual venues for such outcry: XCOM 2's Steam reviews page and Metacritic, where one user wrote "I literally can not recall the last game that gave me as much technical difficulties as XCOM 2."
We reached out to 2K, the game's publisher, shortly after launch last week after noticing the issue, they've just written back with a response. "We are aware some players have experienced performance issues while playing XCOM 2, and we are looking into them and gathering more information from users," a 2K Games representative told PC Gamer via email. "We want everyone to have the best experience possible, and will continue supporting the title with upcoming patches."
'Upcoming' seems to signal that a patch is coming relatively soon, but that's my speculation. In the meantime, the official forums for XCOM 2 has a guide to tech troubleshooting that may help you manage issues you're experiencing.