Tested this on the latest main branch.
Not sure if this is the same issue but I can reproduce this even without the steps above.
Steps:
On a freshly installed app, press the plus button
Open a nested folder (DCIM/Screenshots in my example)
As seen in the below video, some of the images are gray and some are not.
As expected, when I add the folder as root and view its contents, I can see all the images.
Steps to reproduce:
https://user-images.githubusercontent.com/581023/134819865-d4c47341-a904-4f62-8719-8cda387169b6.mp4