Why is the drive usage inaccurate?
The storage usage of a drive is asynchronously calculated. The result may be returned with a latency.
Why does a new user not have a drive?
Check whether the initial drive feature is enabled for the domain to which the user belongs. After the initial drive feature is enabled for the domain, Photo and Drive Service (PDS) automatically creates an initial drive for a user when the user logs on to PDS for the first time.