The landscape and portrait layout settings reset to "default" every time a 3DS game starts, regardless of how I set it in settings. They also revert to "default" when the device is rotated or when a controller is connected. (3.0.4 - iPhone 16 Plus - iOS 18.3.1)
#EmuThreeDS portrait and landscape settings keep resetting
viscid orbit
plain stream
The settings are never applied even if they remain. This has been my issue ever since it released.