A few days ago I installed the update to Android 10 on my Moto G7 power. The file manager integrated in Kurviger pro app no longer works. Subfolders are no longer displayed and you cannot select anything. I cannot open maps nor routing files. See the screenshot. With Android 9 everything worked well.
Have you granted the storage permission when asked by the file manager?
Or you can do that in Android permission settings.
You are at the top folder: “/storage/emulated/0”. Can you enter that folder?
You can uninstall / reinstall the app or clear the app data in Android settings,
to reset app state (just backup / export your bookmarks / routes before that).