Because you can hear it does not mean it will be recorded. What you "monitor" is often a separate feed from what is going to be recorded. The reasons for this a matter of the signal routing.

In general, an external devices like your Motif XF and/or your Tyros3 are going to be, most often, monitored "direct" (that is, not going through the computer), the computer must receive audio, time stamp it, print it to the hard drive, then send the audio to the audio interface... The extra amount of time for all this to happen is called "latency". So it is pretty standard operating procedure to route their signal 'direct' to the monitor system (a duplicate routing is sent to the computer to be recorded, but you select just to listen to the non-latent, direct signal. You hear the recorded version afterwards, during playback.

In a typical situation when using the computer both as recorder and tone generator, as is the case with any plugin software synth, you normally keep the audio "virtual". That is, you do not print it to an audio track, at all, initially. The computer is generating the audio which you "monitor" to through the VST routing (through the VST INSTRUMENT folder's Audio Lane. It is a what-you-hear-is-what-you-are-going-to-get when you finally render the "virtual" audio to actual audio. This happens in Cubase through a FILE process called EXPORT > Audio Mixdown. This is not a real time process, but happens when you execute the File routine. This is when the MIDI data recorded to the VST MIDI Track for the soft synth is used render an audio track. You fill in the dialog box and the computer creates an actual Audio Wave and Cubase creates an Audio Track to house the data.

So one workflow would have you recording MIDI data for the plugin piano to Cubase... Then in a separate operation render audio using Export Audio Mixdown...

EXTRA CREDIT:
The audio you are returning from Ivory to the XF, is probably going directly to your monitor speakers. Because audio coming from the computer going to the Motif XF (via FW16E) is typically assigned to go directly to the "Main L/R" Outputs.

There are 6 audio returns from the computer going to the Motif XF (FW16E)... 3 stereo pairs:

Main L/R - as you know these are connected to your monitoring system - the main Left/Right output jacks on the XF back panel
Asgn L/R - the Assignable 1/4" jacks on the Motif XF's back panel (often used to run a headphone system for multiple musician sessions)
FW L/R - this pair arrives in the Motif XF's internal mixer, where you can sample it, or route it on its own discreet bus back to Cubase to be recorded as actual audio.

You will have to determine what works best for your particular situation. You have a couple of options. We recommend you follow the route that allow your particular plugin and computer to work best. In general, plugin soft synths anticipate you're going to record MIDI, initially, then render audio in a separate operation.

Let us know if you have addition questions.

Thanks BM. I need to think about your response and do some testing. I think I understand. I will post if I have more questions. Thanks again.

Joe

BM

Your recommendations worked. I added Ivory as a Cubase plugin and used it in MIDI track as a VST Instrument. Once I did that it recorded and I can hear it when I play back the project. When I mixdown the project my audio and MIDI tracks are included. Synthogy who developed Ivory said it needed to be a plugin rather than a standalone.

Still have yourto check to see if Ivory as a plugin is now sensitive to the FWPart parameters.