Very low FPS at native resolution and slow terrain loading

When I set the game to its native resolution, the FPS dropped to 20, which seems ridiculously low to me. At 66% resolution scaling, it stayed around 30–40 FPS, which is still quite low. It only runs smoothly at 60 FPS when using 50% resolution scaling. All the other settings were set to Ultra. From what I’ve seen, the game seems to be capped at 60 FPS, so the unlimited FPS option feels pointless. Regarding the slow loading, while flying on Koraidon, terrain-loading notifications kept appearing constantly, and the terrain never loaded fast enough to keep up with the flight speed. Graphically, the game looks amazing, but its performance is very poor. It has improved compared to the previous version, which was practically unplayable due to the extremely low FPS.