Drawdown FPS (Call of Duty Black Ops: Cold War)

System: i7 6700k, mother of asus h170pro, 16g ddr4 2400, ssd (don't remember), rtx3060ti.
The problem is a sharp drop in FPS. Sometimes from 110 to 55, more often it does not show above 70 at all and jumps to 35. Vidyuhu testit has no problems in it more than once, the RAM is also stable, the CPU loads up to 80% during the game and keeps 57-63 degrees. Windows 10 is clean, except for witchcraft, nothing is installed from the games. I don't even know what the problem might be. Any thoughts on this?