Change the private IP address of VM1 to static
Box 1: Remove the public IP address from VM1
Note: A public load balancer can provide outbound connections for virtual machines (VMs) inside your virtual network. These connections are accomplished by translating their private IP addresses to public IP addresses. Public Load Balancers are used to load balance internet traffic to your VMs.
Box 2: Create and configure an NSG
NSGs are used to explicitly permit allowed traffic. If you do not have an NSG on a subnet or NIC of your virtual machine resource, traffic is not allowed to reach this resource.
Reference:
https://docs.microsoft.com/en-us/azure/load-balancer/load-balancer-overview
