The title sums up the problem. I’ve had success with every other game running at the native 60 FPS on this external monitor. I went through windows and NVIDIA settings to double check the set framerate of the monitor while in/out of the game. Anyone else having this problem?
Could you check if when you lunch the game the windows option for that monitor is change it to 30hz? Sometimes happens that when you use multiple screens and lunch a game the hz chages automatically.
Also check in game setting if you don’t have fps lock.
Also you can try to lock the fps to 60 with rivaturner.