grayed out import settings means that it's disabled, please enable it in the settings again.
i have the same problem "it is enabled on Lightroom Desktop. I want to automatically import my camera roll pictures into LR mobile to get hem back to LR desktop
Just make sure the "Auto Add Videos" and "Auto Add Photos" are enabled from the sidebar of the app (the "Lr" icon on the top left point of the app). I got a little confused about why stuff wasn't auto adding because in previous versions this functionality was enabled on a collection by collection basis, whereas now it's possible to enable it universally irrespective of collections (i.e. if you enable this functionality without having any specific collections in Lr mobile, it will still auto add content to the "Lightroom Photos" master collection).
Screenshot enclosed. Hope this helps.
Now why could I not figure that out... LOL Thanks for your help!