Resolve screen rotation image on Olympus E-PL5

My Olympus PEN Lite E-PL5 has an LCD screen which can be tilted up, and flipped over for selfies. When it’s fully upright the screen flips. When you fold the screen back down, the orientation restores. Today, I flipped the screen up to take a selfie with the family, and when the screen was returned to its normal orientation, the screen remains upside down.

Is there a way to reset the gyro in the device, so it’s aware of its orientation? Or, do I need to factory reset? In which case, how do I do this? The Reset/Myset menu option is disabled, and I can’t find any other factory reset options.