As I'm trying to get my calendar with graph UI or with my daemon app, I get the same unknown error with the http error 404

For my app I got the needed permission Calendars.Read by the admin and added the proper scope. The app works nice, when I run simple query https://graph.microsoft.com/v1.0/users/id, I got the required profile, however as I run /users/id/calendars, it fails as shown above.

The same thing occurs as I just run /me/calendars in MS Graph UI as a ordinary user with only delegated rights.

Any ideas, what I'm missing?