When you deploy Azure VMs across Availability Zones and establish failover solutions within the same Azure region, some restrictions apply:
* You can't use an Azure Basic Load Balancer to create failover cluster solutions based on Windows Server Failover Clustering or Linux Pacemaker. Instead, you need to use the Azure Standard Load Balancer SKU.
References:
https://docs.microsoft.com/en-us/azure/virtual-machines/workloads/sap/sap-ha-availability-zones