If you have an external (MIDI-connected) synth - or even Cubase using a VSTi - it may be interesting to learn if Montage thinks you are releasing a key - or if something else is happening. You can MIDI-connect the synth or play something using the included instruments with Cubase (or your favorite DAW). The experiment being to play a tone engine that is NOT Montage's tone engine and see if the problem persists. If it doesn't - then Montage still thinks you're pressing the key - but something else is happening.

The normal support response to this kind of thing would be to backup everything and do a full initialization where the settings are set back to factory defaults -- and try again. I would personally probably try to troubleshoot a bit first.

I'm experiencing this very same phenomena after updating to 2.5. I have no external anything connected to the synth and there was nothing connected to the synth when I performed the update. This is particularly troubling when playing long synth pads with motion control. It just stops. It also happens when using the sustain pedal on piano sounds - the notes stop.

Not sure how to troubleshoot this as you suggest since there is absolutely no connection to anything. Is there something within the Utility settings that can be used to troubleshoot before doing a reset? And I'm not sure a reset will do that much good unless going backwards since the update seems to be the difference here.

Please advice. Thank you

Let me try again with the suggestion.

You may have your keyboard setup however you want right now. It may not have any MIDI device or PC connected. It may not have any wires at all except for a power cable -- and nothing plugged into any port -- including nothing plugged into any audio output. And you're watching the screen to see note activity. None of this matters to the suggestion.

What I have suggested is to, for the sake of learning something, connect either an external keyboard OR a PC. The only reason to do this is to NOT play Montage with the piano keys attached to Montage - but, instead, play Montage with something external.

Either use a different keyboard (one that isn't another Montage) that you "trust" to have well-behaved note-on / note-off behavior OR use a PC (DAW) to play Montage.

Why?

Because one theory is that the physical keyboard inside your Montage has some defect. And that defect causes notes to "stop".

Now - this isn't the only possibility - but it's a quick thing to test.

You're going to play Montage with something other than the Montage "internal" keyboard to see if the same thing happens.

If the same thing doesn't happen - you've learned something.

If the same thing does happen - you've got more digging to do.

I did read that the behavior you're experiencing seems related to a firmware update. I'm not ignoring that. This is just one of those quick-and-dirty tests which is aimed at taking a major controller and either clearing it or implicating it as the source of the issue. It's one step in the process and apparently not that difficult to test (meaning, it doesn't take much playing to determine you're in the clear or in the mud).

Can I also suggest you record yourself playing as MIDI until this happens. Then play back the MIDI file and see if you get the same behaviour with the recording played back.

Excellent point... record yourself to the internal Recorder... then it will be easy to show how when you reach 128 notes of polyphony the notes will stop... or if there is another cause it too may become apparent.

In general, when reporting an issue it is best to be specific about the program (Performance) Name on which it occurs.
If nothing is connected, what do you consider nothing...?
The Sustain Pedal is certainly, something.... yes, everything counts (especially the *Sustain Pedal* as it is always the primary suspect in any polyphony issues. Other culprits are Envelopes (AEG) that reserve polyphony beyond the necessary length of the sampled sound...
Also are the Performances your custom Performances, or Factory Performances?
Any custom Waveforms used?
Does the issue occur on a Factory Performance, if so which one, specifically. You don’t need to list them all, just any one specifically that can be studied.
This will help us help you track down the cause.

In general, the Factory Performances avoid simple layer upon layer upon layer, when multiple Parts are used there is typically some sort of dynamic allocating of Part usage... where one Part morphs or swaps places with others... if you just layer 8 sounds to all play together, you’ll reduce yourself to just 16 note polyphony (inefficient programming can run you out of polyphony, rather quickly... and running out of polyphony could happen in any firmware -so it’s probably not anything to do with the firmware version.

Record the issue occurring, then post the .mid File and a .X7B (MONTAGE CONNECT) file of the Performance... we can take a look at it.
Let us know.