Graph API: getting list of drive items with app-only permissions

Hi,

I have set up an app with all possible app and delegated permissions for Graph API.

I use app-only token to make requests.

When I try to access mail and mailFolders for every user in organization everything works perfect.

But when I try to access drive items for every user /drive/root/children always return empty list, even when /drive/root returns {'folder': {'childCount': 4}}.

Meanwhile in the Graph Explorer I get the list of children for all users.

Is it possible to retrieve drive items for each users with app-only permissions?

Thanks