Same here until now. Guess it is a memory leak that hopefully will be fixed.What I'm seeing is that I keep having a mostly lag-free game (some occasional stutter in big battles) until I'm 2 hours into a game, then suddenly the bandits' shirts will take some time to render, and battles will stutter more and more.
I find it hard to understand; a game like Assassin's Creed Odyssey, with expansive terrain, gorgeous models and animations, absolutely astonishing water and light scattering simulations... it ran much better than Bannerlord.