Go to Project Settings > Engine > General Settings > Framerate, uncheck Smooth Frame Rate and toggle on Fixed Frame Rate. The Fixed Frame Rate has to be matched to the camera’s video source, in this example is 29.97fps.
Under Time Data Monitor Window, you will see the FPS in the Default Engine Settings is changed to 29.97, which is the same frame rate as that of the camera’s video source.
https://embed.notionlytics.com/wt/ZXlKM2IzSnJjM0JoWTJWVWNtRmphMlZ5U1dRaU9pSnZjRlk0UVVOa2JFSndhemhYWmxvek1tYzVaU0lzSW5CaFoyVkpaQ0k2SWpaak4yRTFPVGN4TXpKaFlqUTJaR1poTURBMU9Ea3lZemN5Tm1Ka05HRXlJbjA9