Issue:

When trying to access an Azure File Share configured with Azure AD Kerberos authentication the user is unable to access the share when they have already been granted a valid access role.

Solution:

After looking at the issue with Azure support it was found that the user was logging into the machine using their SamAccountName and not being issued with a cloud Kerberos TGT. When the user logged into Windows using their UPN, which matched their Azure AD account username, then they were granted a Kerberos ticket and could access the share fine.