Consider the following scenario:
• You publish Windows Explorer (Explorer.exe) as a Windows Server 2008 R2 Remote Desktop Services RemoteApp program.
• In this published Windows Explorer, you add or remove a mapped network drive.
In this scenario, you may notice that the status of the mapped network drive in the Explorer window is not updated although the drive was added or removed successfully.
This is because Windows Explorer replies on the Desktop window to update the status of the mapped network drive. When being published by Remoteapp, the Desktop window doesn't exist inside of Windows Explorer, so the mapped network drives cannot be updated automatically.
To workaround this issue, please press F5 to refresh the status manually.
Microsoft has confirmed this is a known issue in Windows Explorer when being publishing through RemoteApp.