The touch keyboard appears every time when tapping in a RemoteApp / RDS App.
A streamed application is considered as a text field for Windows.
You can change a setting in Microsoft Windows to explicitly enable or disable the touch keyboard with the keyboard button on the task bar (only if you are not in tablet mode).
- In Microsoft Windows, navigate to Settings > Devices > Typing.
- Find the setting "Show the touch keyboard when not in tablet mode and there's no keyboard attached": set this to "off".