Azure Virtual Desktop can`t deploy session host

Copper Contributor
we have addc vm in azure, connected to azure ad with cloud sync
in Azure virtual desktop we using fslogix for user profiles
we had deploy few session hosts in specific OU with Active Directory join and everything was working correctly in test environment
then we delete session hosts to replace them with more powerful hosts but its given error
on this stage 
  "message""At least one resource deployment operation failed. Please list deployment operations for details. Please see for usage details.",
  "details": [
      "message""VM has reported a failure when processing extension 'Microsoft.PowerShell.DSC'. Error message: \"The DSC Extension failed to execute: Error downloading after 17 attempts: The remote name could not be resolved: ''.\r\nMore information about the failure can be found in the logs located under 'C:\\WindowsAzure\\Logs\\Plugins\\Microsoft.Powershell.DSC\\2.83.5' on the VM.\"\r\n\r\nMore information on troubleshooting is available at "
1 Reply
We saw an error similar to this when the AVD hosts wasn't able to resolve the download URLs for the extensions (i.e. DNS error). Can you confirm that the DNS servers set in your Virtual Network are online and available?