Why does my FPS drop from 80 to 40 in Farming Simulator 25?

I was so pumped for my virtual farm, but during large-scale growth calculations, my FPS would suddenly plummet from 80 to 40. I initially tried adding more case fans, but the temperature only dropped by 2℃ per HWMonitor, which was a total waste of money. I then used the GamePP Fan Curve Configuration Panel to move the fan speed threshold from 60℃ down to 45℃ with an aggressive linear curve. Now, CPU frequency is a rock-solid 4.2GHz per CPU-Z, and RTSS shows a stable 72-78 FPS while HWMonitor keeps temps at 68-74℃.