Under Settings then Video the fps has always been set to 60. But sometimes it records in 30 fps and I don't know why that is, can someone help?

It could be the FPS of the game.

My OBS went back to 60 fps so the issue is solved for now.

@dez_Games I knew the FPS of the game, so that wasn't the issue.

@Liv I could try checking the log if I have this issue again. I knew it was recording at 30 because on YouTube uploads you can check the fps under right click > "stats for nerds", and by using frame advance with the < and > keys. I also check video files by its properties or by opening it up in video editing software.