I understand that there's nothing wrong with the game. The reason I advised changing the display driver in the game is because OBS can behave better with capturing a graphics accelerated (or not) display from a game depending on what driver it's using. This has worked for me with other programs. For instance DOSBox changing from "surface" and "overlay" to "opengl" can fix this. Same with other games sometimes when they don't behave on OpenGL, Direct3D, or Vulkan. Sometimes it makes a difference because OBS can be stupid.
Anyway, glad you got it working. Clearly your issue was not the same as what I described above.