Static Internal IP and Static Instance Level IP on one VM

Hi everyone, 

I've assigned a  Static Internal IP address to a Windows VM (Windows 2012 R2 with IIS) and I'm trying to assign a Static Instance Level IP address to the same VM. I have to repeat these steps on 4 different VMs that are part of the same "Cloud Services".
Does anyone know if this is supported? I keep getting the following error:
Update-AzureVM : InternalError : The server encountered an internal error. Please retry the request.
At line:1 char:100
+ ... e "pip01" | Update-AzureVM
+                    ~~~~~~~~~~~~~~
    + CategoryInfo          : CloseError: (:) [Update-AzureVM], CloudException
    + FullyQualifiedErrorId : Microsoft.WindowsAzure.Commands.ServiceManagement.IaaS.UpdateAzureVMCommand

I need both type of  static IP addresses so these VMs can communicate to on premises server through VPN and IIS is accessible via the internet.

Thank you in advance for your help.

Hero Kee