Step 1. Check Veeam ONE Security Group Membership
Check that the user is not included in Veeam ONE security groups (Veeam ONE Administrators, Veeam ONE Power Users or Veeam ONE Read-Only Users). Otherwise, the user will be granted access to the whole infrastructure inventory in Veeam ONE, including VMware vSphere, VMware Cloud Director, Microsoft Hyper-V, Veeam Backup & Replication and Veeam Backup for Microsoft 365.
For details, see Permissions and Security Groups.