Re: the photo app cannot find my pictures
Ah, then we've got the same cause. This is what solved my problem:
1. Using the Microsoft
Files App in your phone, navigate to the location of the folder where your "missing" photos are in. In your case, it should be SD Card/Pictures/Camera Roll.
2. Rename the folder of concern into anything, e.g. "Camera Roll X".
3. Restore the original name of the folder, so from "Camera Roll X" back to "Camera Roll".
4. Head over to the Photo Hub in your phone, you should see either an "Updating" status at the top of the screen or the folder itself with the photos in it.
In my case, I had several folders of photos that were entirely missing. So I had to rename and restore each of them so that they would all appear in my Photo Hub.
Let us know if this works for you.