Make sure that you have the drivers for your Yamaha TF installed and that they’re actually being used by checking the Device → Device Setup → VST Audio System menu. Also press F4 to check how the inputs and outputs are connected.
Nuendo Live is very easy to setup and the majority of its users will be people who are already familiar with Cubase and Nuendo. There aren’t many posts about it here for this reason. There’s also not much reason for Steinberg to update it until either Nuendo receives a major revamp or OS compatibility requires it. It already does what it’s designed to do pretty well.