Weird bugs with rendering/exporting tracks that use Cinematic Studio Strings


I have difficulties with tracks that use Cinematic Studio Strings (CSS) library in Kontakt Player 7.10 with Cubase 12 Pro.

Precisely, when I use export (individual channels) or use Render-in-Place thing, I get bugs in the audio - precisely, for one track with violins two hanging notes appeared (determenistically in the same place). Under the discussion with the developer, the cure to this is to turn off an expression map (that I have created myself, based on the keyswitches). The other cure that helped is to send CC64 with zero value two times in a row for each of these two hanging notes.

The other bug is that with contrabasses some notes gets muted in the render randomly and sometimes also loudness changes in some strange way. Here, turning off expressions maps does not help: the rendered audio track still has issues.

During the actual playback of the project in Cubase, these bugs do not appear! OK, maybe the libraries themselves are not quite robust. HOwever, I do not understand how during export/render, the resultant audio is different from the project one? Why does it happen? Does Cubase gives any information to VST instruments like “we are in exporting mode now”?

Does anyone know how to fix it?

I have tried to increase the audio-interface buffer from 256 samples to 2048 (maximum), but no success.

Best regards