Massive FPS drop after a few minutes into the game (PC)

Hello, I'm new here, and I have a small issue with the Ghost of Tsushima PC version. After I launch the game, I get around 120–130 FPS, which is super smooth. But after some time, my FPS drops massively to 50–55 FPS and sometimes even 30–40 FPS. Especially when I open the menu, it can drop to 15–20. I noticed the FPS tends to drop after I engage in combat (especially after a stand-off), though I’m not sure if that’s the cause. Is there any way to fix this issue? 50 FPS is playable, but it bothers me. My PC specs are: Intel Core i5-12450H, 16 GB RAM, RTX 4070 laptop. Thank you in advance.