Nothing is recorded to the track - so what at this point is not working? I see no data, what happens if in the screenshot you press record and play the keyboard. Let us know.

I'm talking about the glitch sound, which you can "see" at the meter disturbance at the previous screenshot. This happens regardless if I am doing anything at all.
Here is a fresh screenshot showing the glitch while playing back a midi track I recorded with the moxf.
Same stuff happens while playing or recording with the moxf, or, as I said, even I am doing nothing at all.
The glitch sound does not appear when I select the moxf vst from the initial cubase menu.
Also, it does not "record" on the windows task manager (I see no disturbance in the graph there).

I'm talking about the glitch sound, which you can "see" at the meter disturbance at the previous screenshot. This happens regardless if I am doing anything at all.

That is correct, and not a glitch.

Hover your mouse over what you are calling a "glitch" in your Cubase Transport Bar. You will discover it identifies itself as MIDI ACTIVITY meter. The MIDI ACTIVITY is not a glitch, but a meter showing that you have a device that is connected that has a clock. Yes, the MOXF has a clock (controls the Seq, Arps, LFOs, Tempo Effects, etc) which outputs the Midi message (F8) constantly, and it also outputs a status indication (FE)... It is not a glitch but actually it's a feature.

If you would rather not see this, right click on this area of your TRANSPORT BAR and unmark "MIDI ACTIVITY". This will opt out of seeing these constant messages coming from your MOXF. You will now only see MIDI ACTIVITY generated by touching the MOXF keys or controllers, only.

It's a feature not a glitch...

What else is not working or was that it? Exporting this as a .wav
When you select FILE > EXPORT > AUDIO MIXDOWN
and you are using the MOXF VST all data between you Left and Right Markers will be rendered as an Audio Track.

Please create a .wav and have Cubase place it in the "POOL" and create a separate AUDIO TRACK. let us know.

I am referring to it as a glitch because it is something I am listening to, not something I am seeing.
The bar that registers it is not the "midi activity" but the "audio activity". Disabling it does not show it, but it is still heard (also recorded in the relevant moxf lane, as shown in the screenshot).
As for the mixdown, I already reported that it did not work with the settings you suggested (cpu overload persists).

If it is audio activity, verify that your MIC/LINE parameter is set to LINE if you are not using the A/D Input. We realize you may have already done this but we mention it because it is a very common error.

And since it does not sound when using the template, it could be an open A/D input.

As for the mixdown, I already reported that it did not work with the settings you suggested (cpu overload persists).

Yes the setup you created for Export was not going to work as shown. What changes did you make... If you don't mind me asking...

I tried the export with the settings you suggested

44.1kHz, 16-bit. Make sure you mark POOL and AUDIO TRACK.

Meaning that I tried the export with the setting suggested and I still got a cpu overload.
Also, MIC/LINE is set to line and the A/D Input is not involved in the process (neither in software or hardware, at the moxf).
I might have to do a format and reinstall everything, and hope for the best.

I doubt if it has anything do with the install. I wish you could provide the screenshot of the EXPORT option. I've seen every kind of setup mistake there. Perhaps you should contact Steinberg through your MySteinberg Account - they will have more experience with computers and CPU Overload message - exporting should not overload your computer - and it is really not a problem with the MOXF (it is not overloading your CPU, at all)

I had the same problem with Cubase 8.5 Pro and MOXF6
I solved it and I want to share my solutions.
They are two:
1) Use this plugin as insert in the Master channel. It will record as wave everything you are playing back or monitoring (it will catch audio channels and MOXF in QuickSetup6 Mode)
2) Bring buffersize to 2048, if you are still having the problem, then it's time for a new PC. I used to have that problem on a older PC (Intel i5 bought in 2010), and I had it sometimes even if buffersize was set to 2048. Now I've bought an Intel i7 (year 2016) and I'm still having the problem if buffersize is set to 64. I have it no more if it's set to 2048.
Please , consider my ideas just like a suggestion. It worked for me, I am not sure that you may have other problems, other causes.
I don't guarantee that buing a new PC it will work, it worked for me.
Anyway, solution number 1 it's free and work 100%
Hope that help.
Luigi