I've got the same thing too. I have a photo on my timeline. I applied the "Lumetri Color" effect on it. When I press "Auto" supposedly the parameters adjust automatically, but they don't. They all remain the same. Funny thing is, premiere pro registers the action of me pressing the button, because when I "ctrl z" it takes the number of times I pressed the button to get back to the original state of not having lumetri color applied on that photo.
So it IS being pressed, but premiere just chooses to do nothing...