I also have a Ryzen 9800X3D (and right next to me on my desk there’s a boxed Ryzen 7 98503D waiting to be installed. More about the tests in the linked thread https://forums.flightsimulator.com/t/ryzen-7-9850x3d-6-faster-than-9800x3d-the-world-s-best-gaming-cpu-tests-comparisons-and-rumors/755705 ) I also have an RTX 4090 and 64GB of DDR5-6000 CL26 RAM. I’m running the latest driver and I’m not experiencing this issue at all.
https://forums.flightsimulator.com/t/nvidia-geforce-game-ready-driver-591-86-discussion/755729/9?u=tenpatrol
I’m genuinely wondering why, with such a strong CPU and an RTX 4090, you’re using frame generation?
I’m also wondering why you capped the FPS to 40. There’s a high chance the monitor panel itself is designed to operate from 48Hz and up, so I wouldn’t recommend limiting FPS below the panel’s capabilities.