The documents stored in my app show up in the iOS 11 files app under “on my iPhone”. The folders in this directory do have the app icon of the corresponding app on their folder.
This works correctly except for my app. For my app it shows the folder with a placeholder icon image only.
I could not find any documentation about this. The icon assets of my app do contain all available icon sizes for iOS 11.
What do I need to do to show my app icon on the folder in files app?
This was only a hiccup on my testing device. After removing the app completely and installing it again the icon in the files app was displaced correctly as expected.