I also checked, all values are False, apparently this function does not work quite correctly.
WRITE_EXTERNAL_STORAGE
READ_EXTERNAL_STORAGE
WRITE_INTERNAL_STORAGE
READ_INTERNAL_STORAGE
Tell me, when you install the application, a message appears to grant data reading rights?
After installing the application, try to grant the rights for the application inside the phone. For example, holding down the app icon, the About app button will appear, and there is an App Permissions button.
In my case, access is granted for storage.