2019 Prius Grille Shutter Inoperative

Hi everyone. I have an 2019 Prius hybrid jap import . Grille shutter inoperative has come on the dash. I have visually checked the front grille but there is nothing stuck between the flaps.
on start up the shutters do move but stay in open position

would i be better changing the whole grill with motor? Anyone done this? If so how easy is it. Can’t find any instructions or video guides at all.
Thank you