A Microsoft Entra tenant is the primary administrative unit that represents an organization within Microsoft's identity platform. It defines the boundary for identity management, access control, and resource governance, and serves as the core entity that connects the organization to Microsoft's cloud services such as Azure and Microsoft 365.

The debug output shows that the UbuntuServer address object successfully resolved an IP, while the webServer did not. The most likely cause is a mismatch in the dynamic address filter or missing tags on the target VM.
Verify the filter used for the dynamic firewall address - The filter category=windows may not match any VM metadata, resulting in no matched addresses.
Verify the tags on the target VM - Ensure that the VM has the correct tags (e.g., category=windows) that match the dynamic address filter to enable resolution.

In an active-active FortiGate ELB/ILB deployment, the inbound NAT rules configured on the external load balancer are used to allow administrative access (e.g., HTTPS, SSH) to the individual FortiGate VMs. Since the public IP is associated with the load balancer, NAT rules are required to map specific ports to backend FortiGate instances for management access.

In an active-active FortiGate cluster deployment in Azure, you must assign the public IP address to an Azure load balancer. This is required because Azure does not support multiple VMs sharing a single public IP directly. The Azure Load Balancer handles inbound traffic and distributes it to the active FortiGate instances.