P9PF Inner screen remaining on when closed

Beginning on Friday morning last week, my Pixel 9 Pro Fold seems to have developed a fault where the inner display doesn't deactivate when I close the phone, preventing the outer display from operating. I can basically force the phone to reactivate the external screen using the "Rear camera selfie" mode in camera but it's a rather inelegantly solution.

Has this happened to anyone else? Any tips or fixes?