My game performance is not as it was before What is the solution?

i have
i7 - 10700f
GTX -1660 SUPER
16 Gb
with SSD

When landing from a plane, my FPS is around 30. When playing inside a building or house, the numbers are much better. However, in open spaces and during clashes with enemies, I get less than 70 FPS. This is not typical of the game on my device, as I always get huge numbers that are acceptable for playing. But suddenly, something sad happens to me. What is the solution? I tried deleting the game, downloading it, deleting Windows, and downloading it again. I also tried making some settings and improvements in Windows, the system, and in the game, but nothing changed. What is the solution?