This is not an error, but rather a question about the emulator.
Does FBN have an option or key to display the FPS of a loaded game? In MAME, I think you can see it with F11, but in FBN I can't find the key.
Best regards.
By the way, the forum is quite slow or has trouble loading the page... it happens on both my PC and cell phone. Other forums or pages load fine.