issue performance

I am experiencing an issue that did not occur previously. The game used to run at ultra settings with a stable 180–170 FPS. However, since a certain point, while the game initially runs perfectly, after some time the FPS begin to drop and freezing becomes increasingly frequent. Additionally, the audio deteriorates to the point where the entire system sound stops working.

I have already tried several solutions, including uninstalling and reinstalling the game, reinstalling the NVIDIA graphics drivers, lowering all settings to minimum, and disabling vertical sync, but the issue persists.